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FOURTEEN WEEKS 



IN 



Human Physiology. 



BY 
J. DORMAN STEELE, Ph. D., 

AUTHOR OF THfi FOURTEEN-WEEKS SERIES IN NATURAL SCIENCE. 



" 'T is the sublime of man, 
Our noontide majesty— to know ourselves, 
Part and proportion of a wondrous whole." 

COLERIDGS, 



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Copyright, 1873, by A. S. Barnes & Co. 
Copyright, 1901, by Esther B. Steele. 

14 W. Physiol. 
w. P. 6 



cy^ 




Cy^^^--d/^,^^^'^^, 






a — ^J 







PREFACE. 



[HE term Physiology, or the science of the fanc- 
tions of the body, has come to include Anatomy, 
or the science of its structure, and Hygiene, or 
the laws of health ; the one being essential to 
the proper understanding of physiology, and the othei 
being its practical application to life. The three are inti- 
tnately blended, and in treating of the different subjects 
the author has drawn no line of distinction where nature 
has made none. This work is not prepared for the use of 
medical students, but for the instruction of youth in the 
principles which underlie the preservation of health and 
the formation of correct physical habits. All else is made 
subservient to this practical knowledge. A simple scien- 
tific dress is used which, while conducing to clearness, 
also gratifies that general desire of children to know some- 
thing of the nomenclature of any study which they 
pursue. 

To the description of each organ is appended an accouni 
of its most common diseases, accidents, etc., and, when 
practicable, their mode of treatment, A pupil may thug 



Vlli PREFACE. 

learn, for example, the cause and cure of a culd, the man- 
agement of a wouLd or the nature of an inflammation. 

The Practical Questions, which have been a prominent 
feature of the series, will be found, it is hoped, equally use- 
ful in this work. Directions for preparing simple micro* 
jcopio objects, and illustrations of the different organs, 
are given under each subject 

In the Appendix will be found Questions for class use, 
Hints about the sick-room, Suggestions as to what to do 
^' till the doctor comes,'^ Antidotes for poisons, and a full 
[ndex. 

Beheving in a Divine Architect of the human form, 
the author cannot refrain from occasionally pointing out 
His inimitable workmanship, and impressing the lesson 
of a Great Final Cause. 

Great pleasure is taken in the acknowledgment of 
special obligations to William 0. Wey, M.D., of Elmira, 
N. Y., President of the N. Y. State Medical Society, who 
has carefully read the work both in manuscript and in 
proof, and has added many valuable hints and illus- 
trations. 

The MS. was also reviewed by L. S. Burbank, A.M., 
Teacher of Natural Science, High School, Lowell, Mass., 
and the proofs by J. W. P. Jenks, A.M., Director of the 
Museum and Lecturer on Nat. Hist., Brown University ; 
0. W. Parsons, M.D., Providence, K. L ; A. P. Stone, AM., 
PrineHigh School, Portland, Me.; S. G. Williams, Ph.D., 
Prin. High School, Cleveland, Ohio ; C. H. Chandler, AM., 



P R E FA C E, IX 

Springfield Eepublican, Springfield, Mass. ; A. D. Small, 
A.M., Sup. Schools, Newport, R. I. ; H. S. Jones, A.M., 
Sup. Schools, Erie, Pa. ; William H. Beach, A.M., Prin, 
High School, and Sam'l Calvin, Prin. Grammar School 
No. 4, Dubuque, Iowa; L. 0. Foster, Prin. Grammai 
School No. 1, Elmira, N. Y., and others, all of whom 
have enriched the book with the fruits of their experi- 
enee. 

The author has gleaned from every field, at home and 
abroad, to secure that which would interest and profit his 
pupils. In general, Flint's great work on the Physiology 
of Man, an undisputed authority on both sides of the 
Atlantic, has been adopted as the standard in digestion, 
respiration, circulation, and the nervous system. Leidy^s 
Human Anatomy, and Sappey's Traite d' Anatomic have 
been followed on aU anatomical questions, and have fur- 
nished many beautiful drawings. Huxley's Physiology 
(London, 1871), has afforded exceedingly valuable aid. 
Hinton's delightful work on Health and its Conditions, 
Black's valuable Ten Laws of Health, Williams's practical 
essay on Our Eyes and How to Use them, Le Pileur's 
charming treatise on The Wonders of the Human Body, 
and that quaint volume, Odd Hours of a Physician, have 
aided the author with facts and fancies. The writings 
Df Draper, Dalton, Carpenter, Valentine, Mapother, Wat- 
son, Lankester, Letheby, Hall, Hamilton, Bell, Wilson, 
Bower, Cutter, Hutchison, Wood, Bigelow, Stille, Holmes, 
Beigel and others have been freely consulted. 



PUBLISHERS' NOTICE. 



The Hygieistic Physiology^ a revision of this work, 
is now ready. It contains mncli new matter, such as 
Blackboard Analyses, a chapter on Ventilation, and also, 
interwoven through the text, a careful treatment of the 
physiological influence of alcohol, tobacco, opium, and 
other narcotics. This is the only work of academic 
grade that has the approval of the Women^s Christian 
Temperance Union. 



SUGGESTIONS TO TEACHERS. 




SEEING is belieying ; — more than that ; it is often 
knowing and remembering. The mere reading 

^^^ of a statement is of httle value compared with 
the observation of a fact. Every opportunity should 
therefore be taken of exhibiting to the pupil the phe- 
nomena described, and thus making them real. A micro- 
scope is so essential to the understanding of many subjects, 
that it is indispensable to the proper teaching of Physiol- 
ogy. A suitable instrument and carefully prepared spec- 
imens showing the structure of the bones, the skin, and 
the blood of various animals, the pigment cells of the 
eye, etc., may be obtained at a small cost from the Pub- 
hshers of this book. They also keep for sale models of 
all the organs. These were prepared under the super- 
vision of Dr. Bock, Prof of Anatomy in the University of 
Leipsic, and will be found exceedingly valuable. 

On naming the subject of a paragraph, the pupil should 
be prepared to tell all he knows about it. No failure 
should discourage the teacher in establishing this mode 
of study and recitation. A little practice will produce th^ 



411 SUO G U S TIONS TO T E A C H E R S -^ 

most satisfactory results. The unexpected question and 
apt reply develop a certain sharpness and readiness which 
are worthy of cultiyation. The questions for review, 
or any others which the wit of the teacher may suggest, 
can be eflfectively used to break the monotony of a topical 
recitation, thereby securing the benefits of both systems. 

The pupil should expect to be questioned each day 
upon any subject passed over during the term, and thus 
the entire knowledge gained will be within his grasp for 
instant use. While some are reciting to the teacher, let 
others write on slates or on the blackboard. At the 
close of the recitation let all criticise the ideas, the spell- 
ing, the use of capitals, the pronunciation, the grammar 
and the mode of expression. Greater accuracy and much 
collateral drill may thus be secured at little expense of 
valuable school-time. 

The Introduction is designed merely to furnish sugges- 
tive material for the first lesson, preparatory to beginning 
the study. Other topics may be found in the questions 
given in the Appendix. 

iVote.— Interest in the study of Physiology will be much increased by the use of 
the microscope and prepared slides. These may be obtained from any good optician. 



TABLE OF CONTENTS. 



PAGB 

IN TROD UCTION 15 

I. 
THE SKELE TON 19 

I I. 
THE MUSCLES 43 

I I I. 
THE SKIN 61 

IV. 
RESPIRA TION AND THE VOICE 83 

V. 
THE CIRCULATION 105 

VI, 
DIGESTION AND FOOD 133 

VII. 
THE NERVOUS SYSTEM ... ,_ 159 



iX\ TABLE OF C NTE N T 8c 

^ ^^ * * • PAGB 

THE SPECIAL SENSES 179 

1. TOUCH 179 

2. TASTE 181 

2, SMELL 182 

4. HEARING 184 

5. SIGHT 187 

IX. 
CONCLUSION 197 

X. 

APPENDIX , 203 

1. HINTS ABOUT THE SICK-ROOM 203 

2. DISINFECTANTS 204 

3. WHAT TO DO ' TILL THE DOCTOR COMES'' 204 

4. ANTIDOTES TO POISONS 209 

5. QUESTIONS FOR CLA SS USE 211 

6. ANALYSIS OF THE SKELETON. 230 

'S^INDEX - 232 



INTRODUCTION 




'HYSIOLOGIOAL STUDY in youth is of in. 
estimable value. Precious lives are frequently 
lost through ignorance. Thousands squander 
in early years the strength which should have 
been kept for the work of real life. Habits are often 
formed in youth which entail weakness and poverty upon 
manhood and are a cause of life-long regret. The use of 
a strained limb may permanently damage ifc. Some silly 
feat of strength may produce an irreparable injury. A 
thoughtless hour of reading by twilight may impair the 
sight for life. A terrible accident may happen, and a dear 
friend perish before our eyes, while we stand by powerless 
to render the assistance we could so easily give did we 
'' only know what to do.'' The thousand little hints which 
may save or lengthen life, may repel or abate disease, 
or the simple laws which regulate our bodily vigor, should 
oe so familiar that we may be quick to apply them in an 
emergency. The preservation of health is easier than the 
sure of disease. Childhood cannot afford to wait for the 
lesson of experience which is learned only when the pen- 
alty of violated law has been already incurred, and health 
irrevocably lost. 

Nature's Laws Inviolable. — In infancy we learn how 
terribly nature punishes a violation of certain laws, and 
how promptly she applies the penalty. We soon find out 



XVi INTRODUCTION. 

the peril of fire, falls, edged-tools, and the like. We fail, 
however, to notice the equally sharp and certain punish- 
ments which bad habits entail. We are quick to feel the 
need of food, but not so ready to perceive the danger of an 
excess. A lack of air drives us at once to secure a supply ; 
but foul air is as fatal, yet gives us no warning. Nature 
provides a little training for us at the outset of life, but 
leaves the most for us to learn by bitter experience. So in 
youth we throw away our strength as if it were a burden 
of which we desired to be rid. We eat anything, and at 
any time ; do anything we please, and sit up any number 
of nights with little or no sleep. Because we feel only a 
momentary discomfort from these physical sins, we fondly 
imagine when that is gone we are all right again. Our 
drafts upon our constitution are promptly paid, and we ex- 
pect this will always be the case ; but some day they will 
come back to us protested ; nature will refuse to meet our 
demands, and we shall find ourselves physical bankrupts. 
We are furnished in the beginning with a certain vital 
force upon which we may draw. We can be spendthrifts 
and waste it in youth, or be wise men and husband it to 
manhood. Our shortcomings are all charged against this 
stock. Nature's memory never fails; she keeps the ac- 
count with perfect exactness. Every physical sin subtracts 
from the sum and strength of our years. We may cure a 
disease, but it never leaves us as it found us. We may heal 
a wound, but the scar still shows. We reap as we sow, and 
we may either gather in the thorns, one by one, to tor- 
ment and destroy, or rejoice in the happy harvest of a hale 
old age. 



I 

The Skeleton 



"Not in the world of light alone, 
Where God has built His blazing throne. 
Nor yet alone on earth below, 
With belted seas that come and go, 
And endless isles of sunlit green, 
Is all thy Maker's glory seen — 
Look in upon thy wondrous frame, 
Eternal wisdom still the same ! " 

HOLMEg 



The Skeleton. 



THE Skeleton, or framework, of the "House we 
live in/' is composed of about 200 bones,* 
Uses and Forms of the Bones. — They have three 
principal uses : 1. To protect the deUcate organs ; f 3. To 
serve as levers on which the muscles may act to produce 
motion ; and 3. To preserve the shape of the body. Bones 
differ in form according to the uses they subserve. For 
(convenience in walking, some are long ; for strength and 
compactness, some are short and thick ; for covering a cav- 
ity, some are flat; and for special purposes, some are irreg- 
ular. The general form is such as to combine strength 
and lightness. For example, all the long bones of the 



* The precise number varies in different periods of life. Several which are 
separated in youth become united in old age. Thus five of the vertebrae early 
join in one great bone— the sacrum, and four tiny ones below it often run into a 
bony mass — the coccyx (Fig. 6). (See Analysis of the Skeleton in the Appendix, 
page 230.) 

While, however, the number of the bones is so uncertain, their relative 
length is so exact that the length of the entire skeleton, and thence the height of 
the man, can be obtained by measuring a single one of the principal bonea^ 
Fossil bones and those found at Pompeii have the same proportion as our own. 

+ An organ is a portion of the body designed for a particular use, which is 
called its function. Thus the heart circulates the blood, the liver produces the 
bile. 



20 THE SKELETON. 

limbs are round and hollow, thus giving with the same 
weight a greater strength,* and also a larger surface for 
the attachment of the muscles. 

The Composition of the Bones at maturity is 
about one part animal to two parts mineral matter. The 
proportion yaries with the age. In youth it is nearly half 
and half, while in old age the mineral is greatly in excess. 
By soaking a bone in weak muriatic acid, and thus dis- 
solving the mineral matter, its shape will not change, but 
its stiflfness will disappear, leaving a tough, gristly sub- 
stance f (cartilage), which can be bent hke rubber. 

If the bone be burned in the fire, thus consuming the 
animal matter, the shape will still be the same, but it will 
have lost its tenacity, and the beautiful, pure-white residue J 
may be crumbled into powder with the fingers. 

* Cut a sheet of foolscap in two pieces. Koll one-half into a compact cylin- 
der, and fold the other into a close, flat strip ; support the ends of each, and hang 
weights in the middle until they bend. The superior strength of the roll will 
astonish one unfamiliar with this mechanical principle. In a rod, the particles 
break in succession, first those on the outside, and later those in the centre. In 
a tube, the particles are all arranged where they resist the first strain. Iron pil- 
lars are therefore cast hollow. Stalks of grass and grain are so light as to bend 
before a breath of wind, yet are stiff enough to sustain their load of seed. 

Bone is twice as strong as oak. It would require a weight of 5000 lbs to crush 
a cubic inch.— Mapother. 

t Mix a wineglass of muriatic acid with a pint of water and place In it a 
sheep's rib. In a day or two it will be so soft that it can be tied in a knot. In 
the same way an egg may be made so pliable that it can be crowded into a nar- 
row-necked bottle, within which it will expand and become an object of great 
curiosity to the uninitiated. 

By boiling bones at a high temperature, the animal matter separates in the 
form of gelatin or glue, and is used for soups and jellies. Dogs and cats extract 
the animal matter from the bones which they eat. Fossil bones deposited in 
the grotmd before the creation of man, were found by Cuvier to still contain 
considerable animal matter. Gelatin was actually extracted from the Cambridge 
mastodon, and made into glue. A tolerably nutritious food might thus be man- 
ufactured from bones older than man himself. 

X From bones thus calcined, the phosphorus of the chemist is made. See 
Chemistry, page 120. If the animal matter be not consumed, but only charred, 
the bone will be black and brittle. In this way the "bone-black " of commerce 
ifi manufactured 



THE STRUCTURE OF THE BONES, 



21 



Fig. «. 






We thus see that a bone receives hardness 
and rigidity from its mineral, and tenacity 
and elasticity from its animal matter. 

The entire bone is at fn^st composed of 
cartilage, which gradually ossifies or turns 
to bone.^ Certain portions near the joints 
are long delayed in this process, and by 
their elasticity assist in breaking the shock 
of a fall, f Hence the bones of children 
are tough, are not readily fractured, and 
when broken easily heal again ; while those 
of elderly people are liable to fracture, and 
do not quickly unite. 

The Structure of the Bones. — 
ViThen a bone is saw^d lengthwise, it is 



* The ossification of the bones on the sides and upper 
part of the skull, for example, begins by a roanded spot 
in the middle of each one. From this spot the ossification 
extends outward in every direction, thus gradually ap- 
proaching the edges of the bone. When two adjacent bones 
meet, therefore, there will be a line where their edges are 
in contact with each other, but have not yet united : but 
when more than two bones meet in this way. there will be 
an empty space between them at their point of junction. 
Thus, if you lay down three coins upon the table with 
their edges touching each other, there will be a three-sided 
space in the middle between them ; if you lay do^^^l four 
coins in the same manner, the space between them will be four-sided. Now at 
the back part of the head there is a spot where three bones come together in this 
way, leaving a small three-sided opening between them : this is called the " pos- 
terior fontanelle." On the top of the head four bones come together, leaving 
between them a large four-sided opening: this is called the '" anterior fontaneUe." 

These openings are termed the Fontanelle^, because we can feel the pulsations 
of the brain through them, like the bubbling of water in a fountain. The fon- 
tanelles gradually diminish in size, owing to the growth of the bony parts 
around them, and are completely closed at the age of four years after birth.— 
Dalton's Physiology, p. 361. 

t Frogs and toads, which move by jumping, and consequently receive so many 
Jars, retain these unossified portions nearly through life : while alligators and 
turtles, whose position is sprawling, and whose motions are measured, do not 
have them at all.— Leidt 



mM^ 



m 



The thigh-bone or 

femur, sawed 

lengthwise. 



^^ THE SKELETON. 

found to be a compact shell filled with a spongy substance. 
This filling increases in quantity, and becomes more porous 
at the ends of the bone, thus giving greater size to form 
a strong joint, while the solid portion increases near the 
middle, where strength alone is needed. Each fibre of 
this bulky material diminishes the shock of a sudden blow, 
and also acts as a beam to brace the exterior wall. 




A thin slice of bone^ highly magnijied, showing the lacuncB, the tiny tubes {can' 
cUiculi) radiating from them, and four Haversian canals, three seen crosswise 
und one lengthwise. 

In the body, bones are not the dry, dead, blanched things 
they seem to be, but are moist, living, pinkish structures, 
covered with a tough membrane called the per-i-os'-te-um,^ 



* The relations of the periosteum to the bone are very interesting. Instances 
are on record where the "bone had been removed, leaving the periosteum, from 
which the entire bone was afterward renewedc 



0ROWTH OF THE BONEb ^ 

{pert, aronndjand osteon, a bone), and the hollow filled 
with marrow, rich in fat and full of blood-vessels. If we 
examine a thin slice with the microscope,we shall see black 
spots with lines running in all directions, and looking very 
hke minute insects. These are really little cavities called 
la-cu-7i(B,* from which radiate tiny tubes. The lacunae 
are arranged in circles around larger tubes, termed from 
their discoverer, Haversian canals, which serve as passages 
for the blood-vessels which supply the bone. The outer 
ends of the canals connect with the blood-vessels of the 
periosteum, and, if the bone is hollow, the inner ends, 
with those of the marrow. 

GroTVth of the Bones. — By means of this system of 
canals, the blood circulates as freely through the bones as 
any part of the body. The whole structure is constantly 
but slowly changing,! old material being taken out and 
new put in. A curious illustration is seen in the fact that 
if madder be mixed with the food of pigs, it will tinge 
their bones red. 

Repair of the Bones. — When a bone is broken, the 
blood at once oozes out of the fractured ends. This soon 
gives place to a watery fluid, which in a fortnight thickens 
to a gristly substance strong enough to hold them in place. 
Bone-matter is then slowly deposited, which in five or six 
weeks will unite the broken parts. Nature, at first, appar- 
ently endeavors to remedy the weakness of the material by 
excess in the quantity, and so the new portion is larger than 



* When the bone is dry, the lacunsB are filled with air, which refracts the light, 
eo that none of it reaches the eye. 

t Bone is sometimes produced with surprising rapidity. The great Irish Elk 
is calculated by Prof. Owen to have cast off and renewed annually in its antlers 
eighty pounds of bone 



^^ THE SKELETON. 

the old. But the extra matter will be gi^adnally absorbed, 
sometimes so perfectly as to leave no trace of the injury. 
A broken limb should always be held in place by sphnts 
to enable this process to go on uninterruptedly, and also 
lest a sudden jar might rupture the partially mended break. 
For a long time the new portion consists largely of animal 
matter, and so is tender and phable. The utmost care is 
therefore necessary to prevent a malformation. 

The Joints are packed with a soft, smooth cartilage 
or gristle, which fits so perfectly as often to be air-tight. 
Upon convex surfaces it is thickest at the middle, and upon 
concave, at the edge, or where the wear is greatest. In 
addition, the ends of the bones are covered with a thin 
membrane, the synovial {sun, with ; ovum, an egg), which 
secretes a viscid fluid, not unlike the white of an egg. 
This lubricates the joints, and prevents the noise and 
wear of friction. The body is the only machine that oils 
itself. 

The bones which form the joint are tied with stout liga- 
ments (ligOy I bind), or bands of a smooth, silvery white 
tissue,* so strong that the bones are sometimes broken with- 
out injuring the fastenings. 

Classification of the Bones. — For convenience the 
bones of the skeleton are considered in three divisions : 
the heady the trunh, and the limbs. 



* The general term tissite is applied to the various textures of which the 
organs are composed. For example, the osseous tissue forms the bones ; the 
ilbroiig tissue, the muscles. 



THE HEAD 



%f. 



THE HEAD 

Fig. h- 




The 8kuU.—l^ frontal bone; ^, parietal bone ; 3, temporal bone; A, the spJienold 
bone ; 5, ethmoid bone ; 6, superior maxillary {upper jaw) bone ; 7, malar bone : 
S, lachrymal bone ; 9, nasal bone ; 10^ inferior maxillary {lower Jaw) bone. 

The Bones of the Skull and the Face form a 
cavity for the protection of the brain and four organs of 
sense, yiz. : sight, smell, taste, and hearing. All of these 
bones are immoyable except the lower jaw, which is 
hinged * at the back so as to allow the opening and shut- 
ting of the mouth. 

The Skull is composed of two compact plates, with 

* A ring of cartilage is inserted in its joints, something after the manner of a 
washer in machinery. This follows the movements of the jaw, ana admits of 
freer motion, while it guards against dislocation. 



^6 THE SKELETON. 

a spongy layer betweeD, These are in several pieces, the 
outer ones being joined by notched edges (sutures, sut'- 
yurs) in the way carpenters term dove-tailing. (See 
Figs. 1, 4.) The peculiar structure and form of the skull 
afford a perfect shelter for the brain — an organ so deh 
cate that, if unprotected, an ordinary blow failing upon it 
would destroy it forever. Its oval or egg shape adapts it 
to resist pressure. The smaller and stronger end is in 
front, where the danger is greatest. Projections before and 
behind shield the less protected parts. The hard plates 
are not easy to penetrate.* The spongy packing deadens 
every blow, f The separate pieces with their curious join- 
ings disperse any jar which one may receive, and also 
prevent fractures from spreading. The frequent open- 
ings in this strong bone-box afford safe avenues for the 
passage of numerous nerves and arteries which serve as a 
means of communication between the brain and the rest 
of the body. 

* Instances have been known where bullets striking against the sknll havis 
glanced off, been flattened, or e\en split into halves. In the Peninsular Cam- 
paign, the author saw a man who had been struck in the forehead by a bullet 
which, instead of penetrating the brain, had followed the skull around to the 
back of the head, and there passed out. 

Fig. 5. t An experiment resembling the familiar one of the balls 

in Natural Philosophy (see Physics, Figure 7, page 30), 

beautifully illustrates this point. Several balls of ivory are 

suspended by cords, as in Fig. 5. If A be raised and then 

let fall, it will transmit the force to B, and that to C, and so 

^ , . . ^ on until F is reached, which will fly off with the impulse. II 

A ?r^P w ^^ '^ ^ ^^^ ^^ spongy bone be substituted for an ivory one 

•^ anywhere in the line, the force will be checked, and the last 

b^ wiU not itir. 




TffE SPINAL COLUMJt. 



THE TRUNK. 

The Trunk has two important cav- 
ities. Tlie upper part, or chest, con- 
tains the heart and the lungs, and the 
lower part, or abdomen, holds the stom- 
ach, liyer, kidneys and other organs. 
(See Fig. 31.) The principal bones are 
those of the spine, the ribs, and the 
hips. 

The Spine consists of twenty-four 
bones, between which are placed pads 
of cartilage."* A canal is hollowed out 
of the column for the safe passage of 
the spinal cord. (See Fig. 48.) Pro- 
jections (processes) at the back and on 
either side are abundant for the attach- 
ment of the muscles. The packing 
acts as a cushion to preyent any jar 
from reaching the brain when we jump 
or run, while the double curve of the 
spine also tends to disperse the force 
of a fall. Thus on every side the 
utmost caution is taken to guard that 
precious gem in its casket. 

The Perfection of the Spine sur- 
passes all human contrivances. Its va- 





, 1 

.ertebrce of the 
neck, cervical; 
12 of the back, 
dorsal ; 5 of the 
loins, lumbar; a. the 
sacrum ; b, the coccyx. 



* These pads vary in thickness from one-fourth to one-half an inch. They be- 
come condensed by the weight they bear during the day, so that we are some- 
what shorter at evening than in the morning. Their elasticity causes them to 
Teeume their usual size during the night, or when we lie down for a time. 



^o THE SKELETON, 

rious uses seem a bundle of contradictions. A chain of 
twenty-four bones is made so stiff that it will bear a heavy 
burden, and so flexible that it will bend hke rubber ; yet, 
all the while, transmits no shock, and eyen hides within it 
a dehcate nerye that would thrill with the slightest touch. 
Resting upon it, the brain is borne without a tremor ; and 
clinging to it, the yital organs are carried without fear of 
harm, 

e Fig. 7. 




A. B. 

B, the atlas ; A, the atlas and axis. 

The Skull Articulates with (is jointed to) the spine 
in a peculiar manner. On the top of the upper yertebra 
(atlas*) are two little hollows («, h, Fig. 7), nicely packed 
and lined with the sjraoyial membrane, into which fit the 
corresponding projections on the lower paii: of the skull, 
and thus the head can rock to and fro. The second yer- 
tebra (axis) has a peg, e, which projects through a hole, c, 
in the first. The surfaces of both yertebrae are so smooth 
that they easily glide on each other, and thus, when we 
moye the head sidewise, the atlas turns around the peg, e, 
of the axis. 

The Ribs, also twenty-four in number, are arranged in 



* So called because, as in ancient fable, the god Atlas supported the world on 
hi» shoulders, so in the body this bone bears the head. 




i^ 



The Chest. 



pairs on each side of the chest. At the back they are ali 
attached to the spine. In front, the npper seven pairs are 
tied by cartilages to the breast-bone (sternum) ; three are 
fastened to each other and the cartilage above, and two, 
the floating ribs, are loose. The natural form of the chest 
would be that of a cone diminishing upward. Owing to the 
tightness of the clothing as commonly worn, the reverse is 
often the case. The long, slender ribs give lightness,* the 
arched form confers strength, and the cartilages impart 
elasticity — properties essential to the protection of the 
delicate organs within, and to freedom of motion iu 
respiration. 

* If the chest-wall were in one bone, thick enough to resist a blow, It would 
be unwieldy and heavy. As it is, the separate bones bound by cartilages yield 
ffradually. and diflfiise the force among them all, and so are rarely broken 



M) 



THE S KE L E TO JN. 

Fig. 9. 




The Pelvis : a, the sacrum. 

The Hip-bones, called by anatomists the Innominata, 
or nameless bones, form an irregular basin styled the pelvis 
{pelvis, a basin). In tbe npper part is the foot of the 
spinal column and a wedge-shaped bone termed the sa- 
crum^ (sacred), firmly planted here between the wide* 
spreading and solid bones of the pelvis, like the keystone 
to an arch, and giving a steady support to the heavy bur- 
dens above. 



THE LIMBS. 

Two Sets of Limbs branch from the trunk, viz.; 
the upper and the lower. They closely resemble each 
other. The arm corresponds to the thigh, the forearm 
to the leg, the wrist to the ankle, the fingers to th« 

* 80 called because it was anciently offered in sacrifice 



THE SHOULDER. 



31 



Fig. 10. 



toes. The fingers and toes are so much ahke that they 
receive the same name, digits, while the several bones 
of both have also the common appellation, phalanges. 
The differences which exist grow out of their varying 
use^ The foot is characterized by strength, the hand by 
mobility. 

The Upper Limbs. — The Shoulder. — The bones of 
the shoulder are the collar-bone (clavicle), and the shoulder- 
blade (scapula). The clavicle {clavis, a key) is a long, 
slender bone, shaped like the Italic/. It is fastened at one 
end to the breast-bone and the first rib, and at the other, 
to the shoulder-blade. (See Fig. 1.) It thus holds the shoul- 
der-joint out from the chest and gives the arm greater play. 
If it be removed or broken, the 
head of the arm-bone will fall, 
and the motions of the arm be 
greatly restricted.* 

The Shoulder-blade is a 
thin, flat, triangular bone, fitted 
to the top and back of the chest, 
and designed to give a founda- 
tion for the muscles of the 
shoulder. 

The Shoulder-joint— The 
arm-bone, or humerus, articu- 
lates with the shoulder-blade by 
i ball-and-socket joint. This 
consists of a cup-like cavity in 
the latter bone, and a rounded 




The Shmilder -joint : ?i. the 
clavicle ; b, the scapvla. 



♦Animals which use the forelegs only for support, do not possess this bone.— 

LSIDT. 



THE SKELETON. 



H- 




^^^' 11' heafi m the former, to fit it,— 

thus affording a free rotary 
motion. The shallowness of 
the socket accounts for the 
frequent dislocation of this 
joint, but a deeper one would 
diminish the easy swing of the 
arm. 

The Elbow.— At the el- 
bow the humerus articulates 
with the uhia—Si slender bone 
on the inner side of the fore- 
arm — by a hinge-joint which 
admits of motion in only two 
directions, i. e., backward and 
forward. The ulna at its low- 
er end is small, and assists but 
slightly in forming the wrist- 
joint. The radius, or large 
bone of the forearm is, on the contrary, small at its upper 
end, and enters but little into^ the elbow-joint, while it is 
large at its lower end and constitutes the greater part of 
the wrist-joint. At the elbow, the head of the radius is 
convex and fits into a shallow cayity in the ulna, while at 
the wTist the nlna plays in a similar socket in the radius. 
Thus the radius may roll over and even cross the ulna. 

The Wrist, or carpus, consists of two rows of yerj 
irregular bones; one of which articulates with the arm, and 
the other with the hand. They are placed side to side 
and so firmly fastened as to admit of only a gliding mo- 
tion. This gives little play, but great strength, elasticity, 
and power of resisting shocks. 



B A 

Bones of the right Forearm ; H, 
the humerus ; R, the radius ; and U, 
the ulna. 



THE HAND 




The Hand.— The met- y- ^ 

acarpal {meta, beyond, and /C^ ^%^ 

karpos, wrist), or bones of 
the pahn, support each a 
thumb or finger. The first 
bone of the thumb, stand- 
ing apart from the rest, 
enjoys a special freedom of 
motion, and adds gi^eatly 
to the usefulness of the 
hand. The first bone (Figs. 
11, 12) of each finger is so 
attached to the correspond- 
ing metacai'pal bone as to 
move in several directions 
upon it, but the other pha- 
langes form hinge-joints. The fingers are named in order ; 
the thumb, the index, the middle, the ring, and the little 
finger. Their difierent lengths cause them to fit the hol- 
low of the hand when it is closed, and probably enable 
us more easily to grasp objects of varying size. If the 
hand clasps a ball, the tips of the fingers will be in a 
straight hue. 

The hand in its perfection belongs only to man. Its ele- 
gance of outline, delicacy of mould, and beauty of color, 
have made it the study of artists ; while its exquisite mo- 
bility, and adaptation as a perfect instrument, have led 
many philosophers to attribute man's superiority even 
more to the hand than to the mind.* 



Bones of the Hand and the Wrist. 



* How conetantly the hand aids ns In explaining or enforcinc: a thought I We 
affirm a fact hy placing the hand as if we would rest it firmly on a body ; we 
deny by a gesture putting the falee or errnneoup nroposition away from us: 



u 



TME SKELETON. 



^^ 




The mp-Joint 

The Lower Limbs. — The Hip. — The thigh-bone, or 
femur^ is the largest and necessarily the strongest in the 
skeleton, since at every step it has to bear the weight of the 
whole body. It articulates with the hip-bone by a " ball- 
and-socket^* joint. Unlike the shonlder-joint, the cup 
here is deep, thus affording less play but greater strength. 
It fits so tightly that the pressure of the air largely aids in 
'Keeping the bones in place.* Indeed, when the muscles 

we express doubt by holding the hand suspended, as if hesitating whether to 
take or reject. When we part from dear friends, or greet them again after long 
absence, the hand extends toward them as if to retain, or to bring them sooner to 
ns. If a recital or a proposition is revolting, we reject it energetically in gesture 
as in thought. In a friendly adieu we wave our good wishes through space to 
him who is the object of them ; but when it expresses enmity, by a brusque 
movement we sever every tie. The open hand is carried backward to express 
fear or horror, as well as to avoid contact ; it goes forward to meet the hand of 
friendship ; it is raised suppliantly in prayer toward Him from whom we hope 
for help \ it caresses lovindy the downy cheek of the infant, and rests on its head 
Invoking the blessing of Heaven. — Wonders of the Human Body, 
* To prove this, a hole was bored through the hip-bone so as to admit air into 



THE FOOT, ifd 

are all cut away, very great force is required to detach the 
limbs. 

The Knee is strengthened by the patella, or knee-pan 
(patella, little dish), a chestnut-shaped bone firmly fas- 
tened over the joint. The shin-bone, or tibia, the large 
triangular bone on the inner side of the leg, articulates 
both with the femur and the foot by a hinge-joint. The 
knee-joint is so made, however, as to admit of a sUght ro- 
tary motion when the hmb is not extended. The Jibula 
(fibula, a clasp), the small outside bone of the leg, is firmly 
bound at both ends to the tibia. (See Fig. 1.) It is im- 
movable, and as the tibia bears the principal weight of the 
body, the chief use of this second bone seems to be to give 
more surface to which the muscles may be attached.* 

The Foot. — The general arrangement of the foot is 
strikingly like that of the hand. The several parts are 
the tarsus, the metatarsus, and the phalanges. The grace- 
ful arch of the foot, and the numerous bones joined by 
cartilages, give an elasticity to the step which could never 
be attained by a single, flat bone. The toes naturally lie 

the socket, when the thigh-bone at once fell out as fiar as the ligaments would 
pennit. An experiment was also devised whereby a suitably prepared hip-joint 
was placed under the receiver of an air-pomp. On exhausting the air the weight 
of the femur caused it to drop out of the socket, while the re-admission of the air 
raised it to its place. 

Without this arrangement, the adjacent muscles would have been compelled 
to bear the additional weight of the thigh-bone every time it was raised. Now 
the pressure of the air rids them of this useless burden, and hence they are less 
easily fatigued,— Weber, 

* A young man in the hospital at Limoges had lost the middle part of his tibia. 
The lost bone was not reproduced, but the fibula, the naturally weak and slender 
part of the leg, became thick and strong enough to support the whole body. — 

CRUVEILHrER. 

An experiment has been performed which illustrates this idea still more strik- 
ingly. An inch of the middle part of the fibula of an animal was cut out. A 
long time afterward the beast was killed, when the tibia was found to have be* 
come considerably larger in that part of it which corresponded exactly with the 
defect in the fibula.— Stant^ky's Lectures. 



36 THE SKELETON-. 

straight forward in the hne of the foot. As we step with 
the bare foot, the ball receiyes the weight first, the sole 
broadens and lengthens, the toes spread, the muscles all 
come in play with the arch of the instep, diffusing and 
breaking the jar ; the heel then settles down under the 
final burden, and affords a firm support. 

Few persons in ciyihzed nations, howeyer, haye naturally- 
formed feet The big toe is crowded upon the others, 
while crossed toes, nails grown-in, enormous joints, corns 
and bunions abound. 

The Cause of these Deformities is found in the 
shape and size of fashionable boots and shoes. The sole 
ought to be large enough for full play of motion, the up- 
pers should not crowd the toes, and the heels should be 
low, flat, and broad. As it is, there is a constant warfare 
between Nature and our shoemakers,* and we are the yic- 
tims. The narrow point in front pinches our toes and 
compels them to oyerride one another ; the narrow sole 
compresses the arch ; while the high heel, by throwing all 
the weight forward on the toes, strains the ankle, and by 
sending the pressure where Nature did not design it to 
fall, causes that joint to become enlarged. The body 
bends forward to meet the demand of this new motion, 
and thus loses its uprightness and beauty, making our 
whole gait stiff and ungraceful. 

Diseases, etc. — 1. The tickets are caused by a 
lack of mineral matter in the bones, rendering them soft 
and phable, so that they bend under the wtight of the 



* When we are measured for boots or shoes, we should stand on a sheet of 
paper and have the shoemaker mark with a pencil the exact outline of our feet as 
they bear our whole weight. When the shoe is made, the sole should exactl;y 
cover tbis outline. 



DiSEASESy ETC. SI 

body. They thus become permanently distorted, and of 
course are weaker than if they were straight.* Tlie dis- 
ease is cured by a more nutritive diet or by taking phos- 
phate of Hme to supply the lack. 

2. A ^el07i is a swelhng of the finger or tht/mb, 
usually of the last joint. It is marked by an accumulation 
of matter beneath the periosteum and next the bone. It 
should be opened so as to prevent the poison collefjted 
there from being absorbed and thus scattered through 
the system. The physician will merely cut through the 
periosteum and let out the effete matter. 

3. S 07 f legs are caused by children standing on their 
feet before the bones of the lower limbs are strong enough 
to bear their weight. The custom of encouraging young 
children to stand up by means of a chair or the support of 
the hand while the bones are yet soft and pliable is a cruel 
one, and liable to produce permanent deformity. Nature 
will set the child on its feet when the proper time comes. 

4. Ctirvature of tJie Spine. — When the spine is 
bent, the packing between the vertebrae becomes com- 
pressed on one side into a wedge-like shape. After a time 
it will lose its elasticity, and the spine become distorted. 
This occurs frequently in the case of students who bend 
forward to bring their eyes nearer their books, instead of 
lifting their books nearer their eyes, or who raise their 
right shoulder above their left when writing at a desk 



* Just here appears an exceedingly beautiful provision. As soon as the dis- 
pi'oportion of animal matter ceases, a larger supply of mineral is sent to the weak 
points, and the bones actually become thicker, denser, harder, and consequently 
stronger at the very concave part where the stress of pressure is greatest.— 
Watson's Lectures on Physic. 

We shall often have occasion to refer to similar wise and providential arrange^ 
ments whereby the body is enabled to remedy defects, and prepare for accl- 
ientB. 



38 THE SKJ&LBTONc 

which is too high. Round shoulders^ small, weak lungs, 
and, oftentimes, diseases of the spine are the consequences. 
An erect posture in reading or writing conduces not alone 
to beauty of form, but also to health of body. 

5. Sprains are produced when the ligaments which 
bind the bones of a joint are strained, twisted, or torn from 
their attachments. They are quite as harmful as a broken 
bone, and require careful attention lest they lead to a 
crippling for life. The use of a sprained limb may per- 
manently impair its usefulness. Hence, the joint should 
be kept quiet, eyen after the immediate pain is gone. 

6. A ^istocation is the forcible displacement of a 
bone from its socket. It is, generally, the result of a fall 
or a violent blow. The tissues of the joint are often 
ruptured, while the contraction of the muscles prevents 
the easy return of the bone to its place. 



PRACTICAL QUESTIONS. 

1. Why does not a fall hurt a child as much as it does a grown 
person ? 

2. Should a young child ever be urged to stand or walk ? 

3. What is meant by " breaking one's neck ? " ^ 

4. Should chairs or benches have straight backs ? 

5. Should a child's feet be allowed to dangle from a high seat 1 

6. Why can we tell whether a fowl is young by pressing on the 
point of the breast-bone ? 

7. What is the use of the marrow in the bones ? 

8. Why is the shoulder so often put out of joint ? 

9. How can you tie a knot in a bone ? 

10. Why are high pillows injurious ? 

11. Is the " Grecian bend" a healthful position ? 

12. Should a boot have a heel-piece ? 

18. Why should one always sit and walk erect ? 

14. Why does a young child creep rather than walk ? 

15. What would be the natural direction of the big toe \ 



II. 

The Muscles. 



*' Behold the outward moving frame, 
Its living marbles jointed strong, 
With glistening band and silvery thong, 
And link'd to reason's guiding reins, 
By myriad rings in trembling chains. 
Each graven with the threaded zone 
WbJcih claims it as the Master's own." 

HOLkfBS 



The M uscles 



THE Use of the Muscles. — The skeleton is the im- 
age of death. Its unsightly appearance instinctively 
Yepels us. We have seen, however, what uses it subserves in 
the body, and how the ugly-looking bones abound in nice 
contrivances and ingenious workmanship. In life, the 
framework is hidden by the flesh. This covering is a 
mass of muscles, which not only give form and symmetry 
to the body, but also produce its varied movements. In 
Fig. 14 we see the large exterior muscles. Beneath these 
are many others; while deeply hidden within are tiny, 
delicate ones, too small to be seen with the naked eye- 
There are, in all, about five hundred, each having its 
special use, and all working in exquisite harmony and per- 
fection. The peculiar property of the muscles is their 
power of contraction, whereby they decrease in length and 
increase in thickness. 

Arrangement of the Muscles. — The muscles are ar- 
ranged in pairs,* each with its antagonist, so that as they 

• ** There are only twelve single muscles in the body.*' 



^ THM MUSCLES. 

contract and expand alternately, the bone to whicli they 
are attached is moved to and fro. If you grasp the arm 
ightly with your hand just above the elbow-joint, and 
bend the forearm, you will feel the muscle on the inside 
(Biceps, a. Fig. 14) swell, and become hard and prominent 
while the outside muscle (Triceps, f) will be relaxed 
Now straighten the arm, and the swelling and hardness of 
the inside muscle will vanish, while the outside one will, 
in turn, become rigid. If the muscles on one side of the 
face become palsied, those on the other side draw the 
mouth that way. Squinting is caused by one of the 
straight muscles of the eye (see Fig. 17), contracting more 
strongly than its antagonist. 

Kinds of Muscles. — There are two kinds of muscles^ 
the voluntary, which are under the control of our will, and 
the involuntary J which are not. Thus our hmbs stiffen or 
relax as we please, but the heart beats on by day and by 
night. The eyelid, however, is both voluntary and invol- 
untary, so that while we wink constantly vrithout effort^, 
we can restain or control the motion to a certain extent 

Structure of the Muscles. — K we take a piece of 
lean beef and wash out the red color, we can easily detect 
the fine fibres of which the meat is composed. In boiling 
corned beef for the table, they frequently separate, owing 
to the dissolving of the delicate tissue which bound them 
together. By means of the microscope, we find that these 
fibres are made up of still finer ones, and that each of 
them is composed of a row of small cells arranged like a 
string of beads. This gives the muscles a pecuhar striped 
(striated) appearance.* The binding of so many threads 

♦ Tbc involnxitary muscles consist merely of smooth, fibrous tissue, and fonn 



TBE TE N D I^ S 
F%g. Ik 



U 




Microscopic view of a Muscle 

into one bundle * confers great strength, according to a 
mechanical principle which we see exemphfied in sus- 
pension bridges, where tlie weight is sustained, not by bara 
of iron, bnt by small wires twisted into massive ropes. 

The Tendons. — The ends of the muscles are generally 
attached to the bone by strong, flexible, but inelastic ten- 
dons.f The muscular fibres spring from the sides of the 
tendon, so that more of them can act upon the bone than 
if they went directly to it. Besides, the small, insensible 
tendon can better bear the exposure of passing oyer a 
joint and be more easily lodged in some protecting groove 
than the broad, sensitive muscle. This mode of attach- 
ment gives to the limbs strength and elegance of form. 
Thus, for example, if the large muscles of the arm ex- 
tended to the hand, they would make it bulky and clumsy. 
The tendons, however, reach only to the wrist, whence fine 
cords pass to the fingers. (See Fig. 16.) Here we notice 
two other admirable arrangements. !• If the long tendons 
at the wrist on contracting should rise, projections would 



elieets or membranes in the walls of hollow organs. By their contraction they 
change the size of cavities which they enclose.— Flint. 

* We shall leam hereafter how these fibres are firmly tied together by a mesh 
of fine connective tissae. 

t The tendons may be easily seen in the leg of a turkey as it comes on our 
table ; so, at a thanksgiving dinner, we may study Physiology while we pick th*» 



w 



THE MUSCLES. 



be made and thus the beaaty of 
the slender joint be marred. To 
prevent this, a stout band or 
bracelet of ligament holds them 
down to their place. 3. In or- 
der to allow the tendon which 
moyes the last joint of the fin- 
ger to pass through, the tendon 
which moyes the second joint 
divides at its attachment to the 
bone. (Fig. 16.) This is the 
most economical mode of pack- 
ing the muscles, as any other 
practicable arrangement would 
increase the bulk of the slender 
finger. Since the tendon can- 
not always pull in the direction 
of the desired motion, some con- 
trivance is necessary to meet 
the want. The tendon (B) be- 
longing to one of the muscles 
of the eye, for example, passes 
through a ring of cartilage, and 
thus a rotary motion is secured. 
The Levers of the Body.^ — In producing the mo- 
tions of the body the muscles use the bones as levers. We 




Tendons of the Hand 



* A lever is a stiff bar resting on a point of support, called the fulcrum (F), and 
kaving connected with it a weight (W) to be lifted, and a power (P) to move it. 
Thpre are three classes of levers according to the arrangement of the power, 
weight, and fulcrum. In the 1st class the F is between the P and W ; in the 2d, 
the W is between the P and F ; and in the 3d, the P is between the W and F 
(Fig. 18). A pump-handle is an example of the first, a lemon-squeezer of the 
second, and a pair of fire-tongs of the third.— Bee Physics, pp. 69—71, for a fiiJU 
deecription of thie sublect, and many illustratioas. 



TMJt LMVSRS OF THE BODY. 4? 

J^. 17. 



pr..X.^^^ 



/; 



f 







The Muscles of tfie Right Eye. A, superior straight; B, superior oblique pose- 
ing through apuUey, D ; G, inferior oblique ; H, external straight^ and, hack of 
it^ the internal straight muscle. 

see an illustration of the first class of levers in the move- 
ments of the head. The back or front of the head is the 
weight to be hfted, the backbone is the fulcrum on which 
the lever turns, and the muscles at the back or front of 




g. 18. 

\ 



P vjr 





L n. lEL 

Th£ three classes of Levers, and also the foot as a Lever, 



kB TBB MUSCLES^ 




The Hand as a Lever of 2d. doss, 

the neck are the powers by which we toss or bow the 
head. 

When we raise the body on tiptoe, we have an instance 
of the second class. Here, our toes resting on the ground 
form the fulcrum, the muscle of the calf (Gas-troc-ne-mi- 
us, ;', Fig. 14), acting through the tendon of the heel/ is 
the power, and the weight is borne by the ankle joint. 

An illustration of the third class is found in lifting the 
hand from the elbow. The hand is the weight, the elbow 
the fulcrum, and the power is applied by the biceps mus- 
cle at its attachment to the radius. (A, Fig. 19.) In 
this form of the leyer there is a great loss of force from its 
being apphed at such a distance from the weight, but 
there is a gain of velocity, since the hand moves so far by 
such a slight contraction of the muscle. The hand is re 
quired to perform quick motions, and therefore this modi 

* This is called the tendon of Achilles, and is so named because, as the fable 
runs, when Achilles was an infant his mother held him by the heel while she 
dipped him in the River Styx, whose water had the power of rendering one in- 
vulnerable to any weapon. His heel not being wet, was therefore his weak 
point, and here Paris, at last, directed the fatal arrow which killed the famous 
hero.—" This tendon will bear 1000 lbs. weight before it will break."— Mapother. 

The horse is said to be hamstrung, and so rendered useless, when the tendou 
-^ AoMlles 7ft r^r- 



HOW WB STAND ERECT 



49 



Fig. W. 



of attachment is wisely adopted. The nearer the power is 
appHed to the weight or resistance, tlie more easily the 
work is done. In the lower jaw, for example, the jaw is 
the weight, tlie fulcrum is the hinge-joint at the back, and 
the muscles (Mas'-se-ter, e, Fig. 14) on each side are the 
power.* They act much closer to the resistance than 
ohose in the hand, since here we desire force, and there 
^peed. - ^ 

The Enlargement of the Bones at 
the Joints not only affords greater surface 
for the attachment of the muscles, as we have 
seen, but also enables them to work to better 
advantage. Thus in Fig. 20 it is evident 
that a muscle acting in the line fb would 
not bend the lower limb so easily as if it 
were acting in the line /A, since in the 
former case its force would be about all 
spent in drawing the bones more closely to- 
gether, while in the latter it would pull 
more nearly at a right angle. Thus the ten- 
don /, by passing over the patella, which is itself pushed out 
by the protuberance 5 of the thigh-bone, pulls at a larger 
angle,f and so the leg is thrown forward with ease in walk- 
ing and with great force in kicking. 

How We Stand Erect. — The joints play so easily, 
and the centre of gravity in the body is so far above the 




TTie Knee-joint i 

h, tJie patella ; 

I, tJie tendon. 



* We may feel the contraction of these muscles by placing our hand on the 
face while we work the jaw. The tendon of the muscle (Digastric) which opens 
the jaw passes tnrough a pulley (c, Fig. 14) somewhat like the one in the eye. 

t The chief use of the processes of the spine (see Fig. 6) and other bones is, in 
the same way, to throw out the point on which the power acts as far from the 
fulcrum as possible. The projection of the ulna ('' funny-bone ") behind the 
elbow, and that of the heel-bone to which the tendon of Achilles is attached, are 
excellent illustrations (Fig. 1). 



50 



'HE MUSCLES. 



Mg. n. 



ki^ 



i^ 



'I 



m\\ 



Action of the 
Muscles which 
keep the body 
erect. 



safe only 
violent it 



foot, that the skeleton cannot of itself hold 
our bodies upright. Thus it requires the 
action of many muscles to maintain this 
position. The head so rests upon the spine 
as to tend to fall in front, but the muscles 
of the neck steady it in its place. "^ The 
hips incline forward, but are held erect by 
the strong muscles of the back. The trunk 
is nicely balanced on the head of the thigh- 
bones. The great muscles of the thigh act- 
ing over the knee-pan tend to bend the body 
forward, but the muscles of the calf neu- 
trahze this action. The ankle, the knee, 
and the hip lie in nearly the same hne, and 
thus the weight of the body rests directly 
on the key-stone of the arch of the foot. So 
perfectly do these muscles act that we never 
think of them until science calls our atten- 
tion to the subject, and yet to acquire the 
necessary skill to use them in our infancy 
needed patient lessons, much time, and 
many hard knocks. 

HoTV We Walk. — Walking is as com- 
plex an act as standing. It is really a 
perilous performance, which has become • 
because of constant practice. We see how 
is when we run against a post in the dark, 



* In animalB, the jaws are so heavy, and the place where the head and spine 
join is so far back, that there can be no balance as there is in man. There are 
therefore large muscles in their necks. We readily find that we have none if we 
get on ''all fours" and try to hold up the head. On the other hand, gorillas 
and apes cannot stand erect like man. Their head, trunk, legs, etc., are not 
balanced by muscles, so as to be in line with each other. 



THE MUSCULAR SENSE, ^^ 

and find with what headlong force we were hurling our- 
selves forward. Holmes has well defined walking as a per- 
petual falling with a constant self-recovery. Standing on 
one foot we let the body fall forward, and swing the other 
\eg ahead like a pendulum. Planting that foot on the 
ground to save the body from falling further, we then 
swing the first foot forward again to repeat the same oper- 
ation.* The shorter the pendulum, the more rapidly it 
vibrates; and so short-legged people take quicker and 
shorter steps than long-legged ones.f We are shorter when 
walking than when standing still, because of this falling 
forward to take a step in advance. J We can cany the 
body ahead by purely muscular exertion, but it requires 
more effort. 

In running, we incline the body more, and so, as it were, 
fall faster. When we walK:, one foot is on the ground all 
the time, and there is an instant when both feet are 
planted upon it ; but in running there is an interval of 
time in each step when both feet are off the ground, and 
the body is wholly unsupported. As we step alternately 
with the feet, we are inclined to turn the body first to one 
side and then to the other. This movement is sometimes 
counterbalanced by swinging the hand on the opposite 
side. 

The Muscular Sense. — When we Hft an object, we 
feel a sensation of weight, which we can compare with 

* It is a curious fact that one side of the body tends to out- walk the other ; and 
so when a man is lost in the woods he often goes in a circle and at last comes 
round to the spot whence he started. 

t In this respect Commodore Nutt is to Magrath, whose skeleton, eight and 
one-half feet high, is now in the Dublin Museum, as a little, fast-ticking, French 
U'lntel-clock is to a big, old-fashioned, upright, corner time-piece. 

X Women find that a dress which will swing clear of the ground when they are 
standing still, will drag the street when they are walking. 



52 THE MUSCLES. 

chat experienced in lifting another body.* By care we 
may cultiyate this sense so as to form a very precise esti- 
mate of the weight of a body by balancing it in the hand. 
The muscular sense is useful to us in many ways. It 
guides us in standing or moving. We gratify it when we 
walk erect and with an elastic step, and by dancing, jump- 
ing, skating, and gymnastic exercises. 

Necessity of Exercise. — The effect of exercise upon 
a muscle is very marked, f By use it grows larger, and 
becomes hard, compact, and darker-colored ; by disuse it 
decreases in size, and becomes soft, flabby, and pale. 

Violent exercise, howeyer, is injurious, since we then tear 
down faster than nature can build up. Feats of strength 
are not only hurtful, but dangerous. Often the muscles 
are strained or ruptured and blood-yessels burst in the 
effort to outdo one^s companions. J 

Two thousand years ago Isocrates, the Greek rhetori- 
cian, said, " Exercise for health, not for strength." The 
cultiyation of muscle for its own sake is a return to bar- 
barism, while it enfeebles the mind, and ultimately the 
body. The ancient gymnasts are said to have become 
prematurely old, and the trained performers of our own 



* If a smalt ivory ball be allowed to roU down the cheek toward the lips, it will 
appear to increase in weight. In general, the more sensitive parts of the body 
recognize smaller differences in weight, and the right hand is more accurate than 
the left. We are very apt, however, to judge of the weight of a body from pre- 
vious conceptions. Thus, shortly after Sir Humphrey Davy discovered the metal 
"Potassium, he placed a piece of it in Dr. Pierson's hand, who exclaimed, "Bless 
me I How heavy it is I " Really, however, potassium is so light that it will float 
on water like cork. 

t The greater size of the breast (Pectoral muscle) of a pigeon, as compared 
with tbat of a duck, shows how muscle increases with use. The breast of a 
chicken is white because it is not used for flight, and therefore gets little blood. 

X Instances have been known of children falling dead from having carried to 
excess so pleasant and healthful an amusement as jumping the rope, and of per- 
sons rupturing the tendon of Achilles in dancing. 



WHAT KiyD OF EXERCISE TO TAKE. 5i 

day soon suffer from the strain they put upon their mus. 
cular system. Few men have yigor sufficient to become 
both athletes and scholars. Exercise should, therefore^ 
merely supplement the deficiency of our daily employment 
A sedentary life 7ieeds daily, moderate exercise, which 
always stops short of fatigue. This is a law of health. 

No education is complete which fails to provide for the 
development of the muscles. Eecesses should be as strictly 
devoted to play as study -hours are to work. Were gym- 
nastics or calisthenics as regular an exercise as grammar 
or arithmetic, fewer pupils would be compelled to leave 
school on account of ill health ; while spinal curvatures, 
weak backs, and ungraceful gaits would no longer charac- 
terize so many of our best institutions. 

Time for Exercise. — ^We should not exercise after 
long abstinence from food, nor immediately after a meal, 
unless the meal or the exercise be very light. There is an 
old-fashioned prejudice in favor of exercise before break- 
fast — an hour suited to the strong and healthy, but en- 
tirely unfitted to the weak and delitate. On first rising 
in the morning, the pulse is low, the skin relaxed, and the 
system susceptible to cold. Feeble persons, therefore, need 
to be braced with food before they brave the out-door air. 

"What Kind of Exercise to Take. — For children, 
games are unequalled. Walking, the universal exercise,"^ is 
beneficial, as it takes one into the open air and sunlight 
Running is better, since it employs more muscles, but 
must not be pushed to excess, as it taxes the heart, and 

* The custom of walking, so preTaient in England, has doubtless much to do 
with the superior physique of its people. It is considered nothing for a woman 
to take a walk of eight or ten miles, and long pedestrian excursions are made to 
all parts of the country. The benefits which accrue from such an open-air life 
are sadly needed by the women of our owm country. A walk of half-a-doacD 
Miles ehonld b^ » i?i<j»s«^.ri^ recreation for any healthy person. 



54 THE MUSCLES. 

may lead to disease of that organ. Bowing is more effec- 
tual in its general development of the system. Swim- 
ming employs the muscles of the whole body, and is a yalu^ 
able acquirement, as it may be the means of saving life. 
Horseback riding is a line accomplishment, and refreshes 
mind and body alike. G-ymnastic or calisthenic exercises^ 
when carefully selected, and not indulged immoderately, 
bring into play all the muscles of the body, and become 
preferable to any other mode of in-door exercise. 

The Wonders of the Muscles.— The grace, ease, 
and rapidity with which the muscles contract are aston- 
ishing. By practice they acquire a facility which we call 
mechanical. The yoice may utter 1500 letters in a min - 
ute, yet each requires a distinct position of the vocal or^ 
gans. We train the muscles of the fingers till they glide 
over the keys of the piano, executing the most exquisit*:> 
and difficult harmony. In writing, each letter is formed 
by its peculiar motions, yet we make them so uncon- 
sciously that a skillful penman will describe the most, 
beautiful curves while thinking only of the idea which the 
sentence may express. The mind of the violinist is upon 
the music which his right hand is executing, while his left 
determines the length of the string and the character of 
each note so carefully that not a false sound is heard, al- 
though the variation of a hairs breadth would cause a 
discord. In the arm of a blacksmith the biceps muscle 
may grow into the solidity almost of a club ; the hand of 
a prize-fighter will strike a blow like a sledge-hammer; 
while the engraver traces lines invisible by the naked eye, 
and the fingers of the blind acquire a delicacy that almost 
supplies the place of the missing sense. 

Diseases, etc. — 1. St. Vitus^s S)a7ice is a disease 



DISJ^ASUS, ETC. St 

of the voluntary muscles, whereby they are in frequent, 
irregular, and spasmodic motion beyond the control of the 
will. All causes of excitement, and especially of fear, 
should be avoided, and the general health of the patient 
invigorated. With renewed strength this disease will gen- 
erally pass away. 

2. Convulsions are an involuntary contraction of the 
muscles. Consciousness is wanting, while the limbs may 
be stiff or in spasmodic action. (See Appendix.) 

3. JjOCked'Jaw is a disease in which there are spasms 
and a contraction of the muscles, usually beginning in the 
lower jaw. It is serious, often fatal, yet it is sometimes 
caused by as trivial an injury as the stroke of a whip-lash, 
the lodgement of a bone in the throat, a fish-hook in the 
finger, or the puncture of the sole of the foot by a tack or 
nail. 

4. Gout is an acute pain located chiefly in the small 
joints of the foot, especially those of the great toe, which 
become swollen and extremely sensitive. It is generally 
brought on by high living. 

5. Rheumatism affects mainly the fibrous tissue of 
the larger joints. While gout is the punishment of the 
rich who live luxuriously and indolently, rheumatism more 
frequently afflicts the poor and those who toil. There are 
two common forms of rheumatism — the inflammatory or 
acute, and the chronic. The latter is of long continuance ; 
the former terminates more speedily. The acute form is 
probably a disease of the blood, which carries with it some 
poisonous matter which is deposited where the fibrous tis- 
sue is most abundant. The disease flies from one joint to 
another in the most unaccountable manner, and the pain 
caused by even the slightest motion deprives the sufferer 



56 THE MUSCLE. 

of the use of the disabled part and its muscler, The chief 
danger to be feared is the possibiUty of its going to the 
heart. The utmost precaution should therefore be used 
to prevent such a result. Physicians do nc'" agree upon 
any specific mode of treating this disease. V^arm fomen- 
tations are usually grateful. Chronic rheumatism — the 
result of repeated attacks of the acute — leads to great 
suffering, and oftentimes to disorganization cf the joints, 
and an interference with the movements of the heart. 

6. ZfUmbago is a disease of the muscles of the back."^^ 
It may be so moderate as to produce only a '' lame back.'^ 
or so severe as to disable, as in the case of a ^^ crick in the 
back/^ Strong swimmers who sometimes suddenly drown 
without apparent cause are supposed to be seized in thia 
way. 

7. :?! Ganglion y or what is vulgarly called a " weak ^ 
or" weeping ^^ sinew, is a swelling of a bursa.f It some- 
times becomes so distended by fluid as to be mistaken for 
bone. If on binding something hard upon it for a few 
days it does not disappear, a physician will easily remove it* 

PRACTICAL QUESTIONS. 

1. What class of lever is the foot when we lift a weight on the 
toes? 

* Lumbago is really a form of myalgia, a disease which has its seat in the mus- 
cles, and may thus affect any part of the body. Doubtless much of what is com- 
monly called " liver " or *' kidney complaint *' is only, in one case, myalgia of the 
chest or abdominal walls near the liver, or, in the other, of the back and loins 
near the kidneys. Chronic liver disease is comparatively rare in the northern 
States, and pain in the side is not a prominent symptom, while certain diseases 
of the kidneys, which are as surely fatal as pulmonary consumption, are not at* 
tended by pain in the back opposite these organs. — Wey. 

t A bursa is a small sack containing a lubricating fluia to prevent friction 
where tendons play over hard surfaces. There is one shaped like an hour-glass 
on the wrist, just at the edge of the palm. By pressing back the liquid it con* 
tains, this "bursa may be clearly seen. 



PRACTICAL QUESTIONS. 61 

2. Explain the movement of the body backward and forward, 
when resting upon the thigh-bone as a fulcrum. 

8. What class of lever do we use when we lift the foot while 
sitting down ? 

4. Explain the swing of the arm from the shoulder. 

5. What class of lever is used in bending our fingers ? 

6 What class of lever is our foot when we tap the ground with 
our toes? 

7. What class of lever do we use when we raise ourselves from a 
stooping position ? 

8. What class of lever is the foot when we walk ? 

9. Why can we raise a heavier weight with our hand when lift- 
mg from the elbow than from the shoulder ? 

10. What class of lever do we employ when we are hopping, the 
thigh-bone being bent up toward the body and not used ? 

11. Describe the motions of the bones when we are using a 
gimlet. 

12. WTiy do we tire when we stand erect ? 

13. Why does it rest us to change our work ? 

14 Wliy and when is dancing a beneficial exercise ? 

15. Wliy can we exert greater force with the back teeth than 
with the front ones ? 

16. Why do we lean forward when we wish to rise from a chair t 

17. \^Tiy does the projection of the heel-bone make walking 
easier ? 

18. Does a horse travel with less fatigue over a flat than a hilly 
country ? 

19. Can you move your upper jaw ? 

20. Are people naturally right or left-handed ? 

21. Why can so few persons move their ears by the muscles? 

22. Is the blacksmith's right arm healthier than the left ? 

23. Boys often, though foolishly, thrust a pin into the flesh just 
above the knee. Why is it not painful ? 

24. Will ten-minutes practice in a gymnasium answer for a day's 
3xercise ? 

25. Wliy would an elastic tendon be unfitted to transmit the mo- 
tion of a muscle ? 

26. When one is struck violently on the head, why does he in. 
stantly fall ? 

27. WTiat is the cause of the difference between light and dark 
meat in a fowl ? 



111. 



Th e Skin. 



— A protection from the outer world, it is our only means oi 
communicating with it. Insensible itself, it is the organ oi 
touch. It feels the pressure of a hair, yet bears the weight 
of the body. It yields to every motion of that which it wrap»s 
and holds in place. It hides from view the delicate organs 
within, yet the faintest tint of a thought shines through, while 
the soul paints upon it, as on a canvas, the richest and rarest 
of oolof^ 



Th e Skin, 



THE Skin is a tough, thin, close-fitting garment foi 
the protection of the tender flesh. Its perfect elas- 
ticity beautifully adapts it to every motion of the body, 
We shall learn hereafter that it is more than a mere coyer- 
ing, being an active organ, which does its part in the work 
of keeping in order the house in which we hve. It oils 
itself to preserve its smoothness and delicacy, replaces 
itself as fast as it wears out, and is at once the perfection 
of use and beauty. 

Structure. — What we commonly call the skin— viz., the 
part raised by a blister — is only the cuticle* or covering 
of the cutis or true skin. The latter is full of nerves and 
blood-vessels, while the former neither bleeds f nor gives 
rise to pain, neither suffers with heat nor feels the cold 
The cuticle is composed of small flat cells or scales. These 
are constantly being shed from the surface in the form oi 



♦ Outlcuta, little sTdii. It is often styled the scarf-skin, and also the epidermis 
{epi^ upon ; and derma^ skin). 

t We notice this in shaving ; for if a razor goes below the cuticle it is followed 
by pain and blood. So insensible is this outer layer that we can run a pir 
throxiifh the thick mass at the roots of the nail* without discomfort 




? a vertical section of the cuticle, 
? of scales like d, magnified 250 diameters. 



B, lateral view of the cells. C, flat 



scarf, dandruff, etc., but are as constantly renewed from the 
cutis,* below. 

Under the microscope we can see the round cells of the 
skin^ and how they become flattened and hardened as they 
are forced to the surface. The immense number of these 
cells surpasses comprehension. In one square inch of the 
cuticle, counting only those in a single layer, there are 
more than a billion of horny scales, each complete in itself 
^Harting. 

Value of the Cuticle. — In the palm of the hand, the 
sole of the foot, and other parts especially liable to injury, 
the cuticle is very thick. This is a most admirable pro- 
vision for their protection.f By use it becomes callous and 
horny. The boy who goes out barefoot for the first time, 
^Hreading as if on eggs/' can soon run where he pleases 



* We see how rapidly this chans^e goes on by noticing how soon a stain of any 
kind disappears from the skin. A snake throws off its cuticle entire, and at reg- 
ular intervals. 

t We can hold the hand in strong brine with impunity, but the smart will 
quickly tell us when there is even a scratch in the skin. In vaccination the mat- 
ter must be inserted beneath the cuticle to take effect. Doubtless this membrane 
prevents many poisonous substances from entering the system. -^ 



HAIR AND NAILS, 68 

among thistles and over stones. The blacksmith handles 
hot iron without pain, while the mason lays stones and 
works in lime without scratching or corroding his llesh. 
The Complexion. —In the freshly-made colls on the 
lower side of the cuticle, is a pigment composed of tiny 
grains.* In the varying tint of this coloring-matter lies 
the difference of hue between the blonde and the brunette, 
the European and the African. In the purest complexion 
there is some of this pigment, which, however, disappears 
as the fresh, round, soft cells next to the cutis change into 
the old, flat, horny scales at the surface. Scars are white, 
because this part of the cuticle is not restored. The sun 
has a powerful effect upon the coloring-matter, and so 
we readily ^^tan^^ on exposure to its rays. If the color 
gathers in spots, it forms freckles, f 



HAIR AND NAILS. 

The Hair and the Nails are modified forms of the 
cuticle. 

The Hair is a protection from heat and cold, and 

* These gi'ains are about 20^00 of an inch in diameter, and curiously enough do not 
appear opaque but transparent and nearly colorless. — Marshall. 

t This action of the sun on the pigment of the skin is very marked. Even 
among the Africans the skin is ol)served to lose its intense black color in those 
who live for many months in the shades of the forest. It is said that Asiatic 
and African women confined within the walls of the harem, and thus secluded 
from the sun, are as fair as Europeans. Anitmg the Jews wdio have settled 
in Northern Europe are many of light complexion, wdiile those who live in 
India are as dark as the Hindoos. The black pigment has been known to dis- 
appear during severe illness and a lighter color to be developed in its place. 
Among the negroes are sometimes found people who have no complexion., i, e., 
there is no coloring-matter in their skin, hair, or the iris of their eyes. These 
persons are called Albinos. 



64 



TJSM SKIJ^c 




A hair magnified 600 
diameters. S, the sac (fol- 
licle) ; P, the papilla, show- 
ing the cells and the blood- 
'?(y). 



shields the head from blows. It is 
found on nearly all parts of the body, 
except the palms of the hands and 
the soles of the feet. The outside 
of a hair is hard and compact, and 
consists of a layer of colorless scales, 
which overlie one another like the 
shingles of a house ; the interior is 
porous/ and probably conveys the 
liquids by which it is nourished. 
Each hair grows from a tiny bulb 
(papilla), which is an elevation of the 
cutis at the bottom of a little hollow 
in the skin. From the surface of 
this bulb the hair is produced, like the cuticle, by the 
constant formation of new cells at the bottom. When 
the hair is pulled out, this bulb, if uninjured, will produce 
a new one ; but when once destroyed, it will never grow 
again. The hair has been known to whiten in a single 
night by fear, fright, or nervous excitement. When the 
color has once changed it cannot be restored. f 

* In order to examine a hair, it should be put on the slide of the microscope, 
and covered with a thin glass while a few drops of alcohol are allowed to flow 
between the cover and the slide. This causes the air, which fills the hair and 
prevents our seeing its structure, to escape^ 

t Hair dyes or so-called ''hair restorers" are almost invariably deleterious sub- 
stances, depending for their coloriug properties upon the action of lead or lunai 
caustic. Frequent instances of hair poisoning b ve of late occurred, owing to the 
common use of such dangerous articles. If the growth of the hair be impaired, 
the general constitution or the skin needs tieatmentc This is the work of a 
skillful physician, and not of a patent remedy. Dame Fashion has her repentant 
freaks as well as her ruinous follies, and it is a healthful sign that the era of uni- 
versal hair-dyeing has been blotted out from her present calendar, and the gray 
hairs of age are now honored with the highest place in " style " as well as In 
good-sense and cleanlinesSc 

The hair is said to grow after death. This is due to the fact that by thf 
shrinking of the skin the part below the surface is caused to project, which 1b 
eepeciaily noticeable in the beard. 



THE NAILS. 



66 



mg. iU, 



Wherever hair exists tiny muscles are found, inter- 
laced among the fibres of the skin. These, when con- 
tracting under the influence of 
cold or electricity, pucker up 
the skin and cause the hair 
to stand on end.* The hairs 
themselves are destitute of feel- 
ing. Nerves, however, are found 
in the hollows in which the hair 
is rooted, and so one feels pain 
when it is pulled, f Thus the 
insensible hairs become most 
wonderfully delicate instruments 
to convey an impression of even 
the slightest touch. 

Next to the teeth and bones, 
the hair is the most indestruc- 
tible part of the body, and its 
color is often preserved for many 
years after other portions have 
gone to decay. J 

The Nails protect the ends 
of the tender finger and toe, and 
give us power more firmly to 
grasp and easily to pick up any 
)bject we may desire. They enable us to perform a hnn 
Ired little, mechanical acts which else were impossible. 

* In horses and other animals which are able to shake the whole skin to drive 
away the flies, this muscular tissue is much more fully developed than in man. 

t These nerves are especially abundant in the whiskers of the cat, which are 
used as feelers. 

$ Fine downy hairs so general upon the body have been detected in some frag« 
ments of skin found beneath the heads of the nails by which, centuries ago, 
certain robbers were affixed to the church doors, as a punishment ♦or thev 




A, a perspiratory tube tcith its 

gland ; B, a hair with a muscle 
and two oil-qlands ; C, cuticle ■ 
D, the papillcE ; and 'E.^fat-ceUs 



66 . TMJE SKU^To 

At the same time their delicate color and beautiful out. 
line give a finish of ornament to that most exquisite in- 
strument, the hand. The nail is firmly set in a grooye 
(matrix) in the cuticle, from which it grows at the root 
in length* and from beneath in thickness. As long as 
the matrix at the root is uninjured, the nail will be re^ 
placed after any accident. 



THE MUCOUS MEMBRANE. 

Structure. — At the edges of the openings into the 
body, the skin seems to stop and giye place to a tissue 
which is redder, more sensitiye, more liable to bleed, and 
is moistened by a fluid, or mucus as it is called. Eeally, 
howeyer, the skin does not cease, but passes into a more 
delicate coyering of the same general composition, yiz., an 
outer hard, bloodless, insensible layer, and an inner soft, 
sanguine, neryous one.f Thus eyery part of the body is 
contained'in a kind of double bag, made of the tough skin 
on the outside, and the tender mucous membrane on the 
inside. 

Connective Tissue. — The cutis and the correspond- 
ing layer of the mucous membrane consist of a fibrous 
substance interlaced like felt. It is called connectiye tis- 

* By making a little mark on the nail near the root, we can see week by week 
how rapidly this process goes on, and so form some idea of what a multitude of 
cells must be transformed into the horny matter of the nail. 

t With a dull knife we can scrape from the mucous membrane which lines the 
mouth some of the cuticle for examination under the microscope. In a similar 
waywe can obtain cuticle froru the surface of the bo^y for study and comparison 



CONNECTIVE TISSUE. 61 

sue, because it connects all the different parts of the body. 
It spreads from tiie cutis, invests muscles, bones, and car- 
tilages, and thence passes into the mucous membrane. So 
thoroughly does it permeate the ))ody, that if the other 
tissues were destroyed, it would still give a perfect model 
of every organ. It can be seen in a piece of meat as 
a delicate substance lying between the layers of muscle, 
where it serves to bind together the numerous fibres of 
which they are composed."^ Connective tissue yields gela- 
tine on boiling, and is the part which tans when hides are 
manufactured into leather. It is very elastic, so that 
when you remove your finger after pressing upon the skin, 
no indentation is left.f It varies greatly in character — 
from the mucous membrane, where it is soft and tender, 
to the ligaments and tendons, which it largely composes, 
where it is strong and dense.J 

Fat is deposited as an oil in the cells § of this tissue, 
just beneath the skin (Fig. 24), giving roundness and 
plumpness to the body, and acting as a powerful non-con- 
ductor for the retention of heat. 1| It collects as pads in 
the hollows of the bones, around the joints, and between 
the muscles, causing them to glide more easily upon each 
other. As marrow, it nourishes the skeleton, and also dis- 
tributes the shock of any jar the limb may sustain. It is 

* Sometimes butchers blow air into veal, which fills the tiny cells of this tissue, 
ind causes the meat to appear plump. 

t In dropsy this elasticity is lost by distension, and there is a kind of "pit- 
:ing," as it is called, produced by pressure. 

X The leather made from this tissue varies as greatly, from the tough, thick ox- 
hide to the soft, pliable kid and chamois skin. 

§ So tiny are these cells, that there are over 65,000,000 in a cubic inch of fat.^ 
Valentine. 

II As the cells of the tissue are kept moistened, the liquid does not ooze out, 
but, on drying, it comes to the surface. For this reason a piece of fat feels oily 
when exposed to the air. 



^8 THE SKIJT. 

noticeable, however, that fat does not gather within the 
cranium, the lungs, or the eye-hds, where its accumulation 
would clog the organs. 



THE TEETH. 

The Teeth * are thirty-two in all — there being eight in 
each half jaw, similarly shaped and arranged. In each 
set of eight, the two nearest the middle of the jaw have 
wide, sharp, chisel-like edges, fit for cutting, and hence are 
called incisors. The next corresponds to the great tear- 
ing or holding tooth of the dog, and is styled the canine, 
or eye-tooth. The next two have broader crowns, with 
two points or cusps, and are hence termed the bicuspids. 
The remaining three are much broader, and as they are 
used to crush the food, are called the grinders or molars. 
The incisors and eye-teeth have one fang or root, the others 
have two or three each. 

The Milk-teeth. — We are provided with two sets of 
teeth. The first, or milk-teeth, are small and only twenty 
in number. In each set of five there are two incisors, one 
canine, and two molars. The middle incisors are usually 
cut about the age of seven months, the others at nine 
months, the first molars at twelve months, the canines at 



* Althongh the teetli are always found in connection with the skeleton, and 
are, therefore, figured a^a part of it (Fig. 1), yet they do not properly belong to 
the bones of the body, and are merely set in the solid jaw to insure solidity. 
They are hard, and resemble bony matter, yet they are neither true bone nor are 
they formed in the same manner. " They are properly appendages of the mucous 
membrane, and are developed from it.''— Leidy. " They belong to the Tegu- 
mentary System, which, speaking generally of animals, includes teeth, nails, 
horns, scales, and hairs."— Marshau^. They are therefore classed with the 
mucous membrane, as are the nails and hair with the sMn, 



THE TEETH 



69 



eighteen months, and the remaining molars at two or 
three years of age. The lower teeth precede the corres- 
pondmg upper ones. The time often varies, but the order 
seldom. 

Fig, 25, 




The Teeth at the age of six and one-half years. I, the incisors ; O, the canine ; 
M, the molars ; the last molar is the first of the permanent teeth : F, sacs of th& 
permanent incisors ,• C, of the canine ; B, of the bicuspids; N, of theM.molar ; 
the sac of the 3d. molar is empty.— M.as.suall. 

The Permanent Teeth. — At six years, when the first 
set are usually still perfect, the jaws contain the crowns 
of all the second, except the wisdom-teeth. About this 
age, to meet the wants of the growing body, the crowns of 
the permanent set begin to press against the roots of the 
milk-teeth, which, becoming absorbed, leave the loosened 
teeth to drop out, while the new ones rise and occupy 
their places.^ The central incisors appear at about seven 
years of age, the others at eight ; the first bicuspids at 
nine, the second at ten ; the canines at eleven or twelve ; 
the second f molars at twelve or thirteen, and the last, or 
wisdom-teeth, are sometimes delayed until the twenty- 
second year, or even later. 

* If the milk-teeth do not promptly loosen on the appearance of the second set, 
the former should be at once removed to permit the permanent set to assume 
their natural places. If any fail to come in regularly, or if they crowd the others^ 
a competent dentist should at once be consulted. 

+ The first molar appears much earlier. /See Fis: 86J 



10 



THE SKIN. 



Fig. 27. 




Structure of the Teeth. — The interior of tlie tooth 

consists principally of dentine: a dense substance resem- 
bling bone.* The crown of the tooth, which is exposed 
to wear, is protected by a sheath of 
enamel. This is a hard, glistening, 
white substance, containing only twc 
and a half per cent, of animal matter. 
The fang is covered by a thin layei 
of true bone (cement). At the cen- 
|-Z) tre of the tooth is a cavity filled with 
a soft, reddish-white, pulpy substance 
fall of blood-vessels and nerves. This 
pulp is very sensitive, and toothache 
is caused by its irritation. 

The Fitting of the Tooth into 
the Jai?? is a most admirable con- 
trivancee It is not set, like a nail in 
wood, having the fang in contact with 
the bone; but the socket is lined 
with a membrane which forms a soft 
cushion. While this is in a healthy 
state, it deadens the force of any shock, but when in- 
flamed, becomes the seat of excruciating pain. 

The Decay of the Teeth f is commonly caused 
(1) by portions of the food which become entangled be- 

* In the tnsk of the elephant this is known as ivory 

t Unlike the other portions of the body, there Is no provision made for any 
caange in the permanent teeth. That part, however, which is thus during life 
most liable to change, after death resists it the longest. In deep-sea dredgings 
they are found when aU traces of the frame to which they belonged have dis- 
appeared. Yet hard and incorruptible as they seem, their permanence is only 
relative. Exposed to injury and disease, they break or decay. Even if they 
escape accident, tney yet wear at the crown, are absorbed at the fang, and, in 
time, drop out, thus affording another of the many signs of the limitations Provi- 
dence has fixed to the endurance of our bodies and the length of our lives. 



Vertical section of a 
Molar Toothy moderately 
magnifed. a, enamel of 
tfte' crown^ the lines of 
which indicate the ar- 
rangement of its columns; 
b, dentine ; c, cement; d, 
pulp cavity. 



GLANDS OF THE SKIN. 72 

tween them, and on account of the heat and moisture, 
quickly decompose. Also (2), as the saliya evaporates, ii 
leaves on the teeth a sediment, which we call tartar, 
This collects the organic matter, which rapidly changes. 
and also affords a soil in which a sort of fungus speedily 
springs up. From both these causes the breath becomes 
offensive, and the teeth are injured. 

Preservation of the Teeth. — Children should early 
be taught to brush their teeth at least every morning 
with tepid water, and twice a week with soap and pow- 
dered orris-root. They should also be instructed to re- 
move the particles of food from between the t^eth, after 
each meal, by means of a quill or wooden tooth-pick. 
The enamel once injured is never restored, and the whole 
interior of the tooth is exposed to decay. We should not, 
therefore, crack hard nuts, bite thread, use metal tooth- 
picks, gritty tooth-powders, or any acid that "sets the 
teeth on edge," i. e., that acts upon the enamel. It la 
well also to have the teeth examined yearly by a dentist, 
that any small orifice may be filled, and further decay 
prevented. 



GLANDS OF THE SKIN. 

I. The Oil Glands are clusters of tiny sacs which 
secrete an oil that flows along the duct to the root of the 
hair, and thence oozes out on the cuticle.* (See Fig. 24.) 
This is nature's efficient hair-dressing, and also keeps the 

♦ This secretion is said to vary in different persons, and on that account the 
dog is enabled to track hie master by the scent. 



y^ THE SKIIS 

skin soft and flexible. These glands are not found where 
there is no hair, as on the palm of the hand, and hence at 
those points only can Neater readily soak through the skin 
into the body. They are of considerable size on the face, 
especially about the nose. When obstructed, their contents 
become hard and dark-colored, and are vulgarly called 
^' worms." * 

II. The Perspiratory Glands are fine tubes about 
g^Q of an inch in diameter, and a quarter of an inch in 
length, which run through the cutis, and then coil up in 
little balls. (Fig. 24.) They are found in all parts of 
the body, and in almost incredible numbers. In the palm 
of the hand there are about 2,800 in a single square inch. 
On the back of the neck and trunk, where they are 
fewest, there are yet 400 to the square inch. The total 
number on the body of an adult is estimated at about two 
and a half million. If they were laid end to end, they 
would extend nearly ten miles. f The mouths of these 
glands — " pores," as we commonly call them — may be seen 
with a pocket lens along the fine ridges which cover the 
palm of the hand. 

The Perspiration. — From these openings there con- 
stantly passes a vapor, forming what we call the insensible 
perspiration. Exercise or heat causes it to flow more 
freely, when it condenses on the surface in drops. The 
perspiration consists of about ninety-nine parts water and 



* Though they are not alive, yet, under the microscope, they are sometimes 
found to contain a curious parasite called the pimple-mite, which is supposed to 
consume the superabundant secretion. 

t The current statement, that they would extend twenty-eight miles, is un- 
doubtedly an exaggeration. Krause estimates the total number at 2,381,248, and 
the length of each coil, when unravelled, at yV of an inch, which would make the 
total len^h much less than even the statement in the text. 



ABSORBING POWER OF THE SKIN. IS 

one part solid matter. The amount varies greatly, but 
on the average is, for an adult, not far from two pounds 
per day. The importance of this constant drainage has 
been shown by frequent experiments. Small animals, as 
the rabbit, when coated with varnish so as to close the 
pores, die within twelve hours.* 

The Absorbing Power of the Skin. — We have al- 
ready described two uses of the skin : (1) \t^ protective, (2) 
its exhaling, and now we come (3) to its absorbing power 
This is not so noticeable as the others, and yet it can be 
easily proved. Persons frequently poison their hands with 
the common wood-ivy. Contagious diseases are caught by 
touching a patient, or even his clothing, f Painters absorb 
so much lead through the pores of their hands that they 
are attacked with colic. J Snuff and lard are frequently 
rubbed on the chest of a child suffering with the croup to 
produce vomiting. Seamen in want of water drench their 
clothing in salt spray, and the skin will absorb enough to 
quench thirst. (See Lymphatic System, p. 123.) 

By carefully conducted experiments it has been found 

* Once, on an occasion of great solemnity at Rome, a child was, it is said, 
completely covered with gold leaf, closely applied to the skin, so as to represent, 
according to the idea of that age, the golden glory of an angel or seraph. In a 
few hours after contributing to this pageant, the child died ; the cause being 
suffocation, from stopping the exhalation of the skin ; although, in the igno- 
rance of the common people of those days, the death was attributed to the anger 
of the Deity, and looked upon as a circumstance of evil omen. 

t If one is called upon to handle a dead body, it is well, especially if the persoi 
has died of a contagious disease, to rub the hand with lard or olive-oil. Poison, 
ons matter has been fatally absorbed through the breaking of the cuticle by a 
hang-nail or a simple scratch. There is a story that Napoleon I., when a lieuten- 
ant of artillery, in the heat of battle, seized the rammer and worked the gun of 
an artillery-man who had fallen. From the wood which the soldier had handled, 
Napoleon absorbed a poison which gave him a skin-disease, by which he was 
annoyed the remainder of his life. 

X Cosmetics, powders, hair-dyes, etc., are exceedingly injurious, not only be- 
cause they tend to fill the pores of the skin, but because they often contain 
poifionous matters which are absorbed into the system 



7Jf THE bKIJSr. 

that the skin acts in the same way as the lungs (see 
Respiration, p. 92) in absorbing oxygen from the air, and 
giving off carbonic acid to an appreciable amount. In- 
deed, the skin has not inaptly been styled the third 
!ung.^ 

Hints about Washing and Bathing. — The moment 
of rising froia bed is the proper time for the full wash or 
bath with which one should commence the day. The 
body is then warm, and can endure moderately cool water 
better than at any other time ; it is relaxed, and needs 
bracing, and the nerves, deadened by the night's repose, 
require a gentle stimulus. K the system be strong enough 
to resist the shock, cold water is the most invigorating ; 
if not, a tepid bath will answer. f Before dressing, the 
whole body should be thoroughly rubbed with a coarse 
towel or flesh-brush. At first the friction may be un- 
pleasant, but this sensitiveness will soon be overcome, and 
the keenest pleasure be felt in the hvely glow which fol- 
lows. A bath should not be taken just before nor im- 
mediately after a meal, as it will interfere with the diges- 

* In some of the lo^rer animals it plays a still more important part. Frogs, 
deprived of their luags, breathe with almost undiminished activity, and often 
survive for days. Snakes get their main supply of air through the skin. 

t Many persons have not the conveniences for a bath. To them the following 
plan, which the author has daily employed for years, is commended. The neces- 
sities are : a basin full of soft water, a mild soap, a large sponge or a piece of 
aannel, and two towels — one soft, the other rough. The temperature of the 
j^ater should vary with the season of the year— cold in summer, and tepid in 
{vinter. Rub quickly the entire body with the wet sponge or flannel. (If more 
igreeable, wash and wipe only a part at a time, protecting the rest in cold 
iveather with portions of the clothing.) Dry the sk.„ gently with the soft towel, 
ind, when quite dry, with the rough towel or flesh-brush rub the body briskly 
for four or five minutes till the skin is all aglow. The chest and abdomen need 
Dhe principal rubbing. The roughness of the towel should be accommodated to 
tihe condition of the skin. Enough friction, however, must be given to produce 
at least a gentle warmth, indicative of the reaction necessary to prevent subse- 
quent chill or languor. An invahd will find it exceedingly beneficial if a stout, 
ngorous person produce the reaction by rubbing with the hands. 



BATHING, 70 

tion of the food. Soap should be employed occasionally, 
but its frequent use tends to make the skin dry and 
hard. 

Reaction. — After taking a cold bath there should 
be a prompt reaction. When the surface is chilled by 
cold water, the blood sets to the heart and other vital 
organs, exciting them to more vigorous action, and then 
being thrown back to the surface, it reddens, warms, and 
stimulates the skin to an unwonted degree. This is called 
reaction, and in it lies the invigorating influence of the 
cold bath. If, on the contrary, the skin be heated by a 
hot bath, the blood is drawn to the surface, less blood goes 
to the heart, the circulation decreases, and languor ensues. 
A dash of cool water is both necessary and refreshing at 
its close.* If, after a cold bath, there be felt no glow of 
warmth, but only a chilliness and depression, we are there- 
by warned that either proper means were not taken to 
bring on this reaction, or that the circulation is not vigor- 
ous enough to make such a bath beneficial. The general 
effect of a cool bath is exhilarating, and that of a warm 
one depressing.! Hence the latter should not ordinarily 
be taken oftener than once a week, while the former may 
be enjoyed daily. 

* The Russians are very fond of vapor baths, taken in the following manner. 
A large room is heated by stoves. Red-hot stones being brought in, water is 
thrown upon them, filling the room with steam. The bathers sit on benches 
until they perspire profusely, when they are rubbed with soapsuds and dashed 
with cold water. Sometimes, while in this state of excessive perspiration, they 
run out of doors and leap into snow-banks. 

t The sudden plunge into a cold bath is good for the strong and healthy, but 
too severe for the delicate, One should always wet first the face, neck, and 
chest. It is extremely injurious to stand in a bath with only the feet and 
lower limbs covered by the water, for the blood is thus sent from the extremi 
ties to the heart and internal organs, and they become so burdened that reaction 
may be out of their power. A brisk walk, or a thorough rubbing of the skiu 
before a cold bath or ewim, adds greatly to its valu^ and pleasure. 



To THE SKIN. 

Sea-bathing is exceedingly stimulating, on account of 
the action of the salt and the exciting surroundings. 
Twenty minutes is the utmost hmit for bathing or swim- 
ming in salt or fresh water. A chilly sensation should 
be the signal for instant removal. It is better to leave 
^hile the glow and buoyancy which follow the first plunge 
are still felt. Gentle exercise after a bath is beneficial. 

Clothing in winter, to keep us warm, should repel the 
external cold and retain the heat of the body. In sum- 
mer, to keep us cool, it should not absorb the rays of the 
sun, and should permit the passage of the heat of the 
body. At all seasons it should be porous, to give ready 
escape to the perspiration, and a free admission of air to 
the skin. We can readily apply these essential conditions 
to the difierent kinds of clothing. Linen is soft to the 
touch, and is a good conductor of heat. Hence it is pleas- 
ant for summer wear, but being apt to chill the surface too 
rapidly, it should not be worn next the skin. Cotton is a 
poorer conductor of heat and absorber of moisture, and is 
therefore warmer than linen. It is sufficiently cool for 
summer wear, and aflbrds better protection against sudden 
changes. Woolen absorbs moisture slowly, and contains 
much air in its pores. It is therefore a poor conductor 
of heat, and guards the wearer against the vicissitudes of 
our climate. The outer clothing may be adapted largely 
to ornament, and may be varied to suit our fancy and the 
requirements of society. But the body should be pro- 
tected by plentiful under-clothing, which should be of 
itself sufficient to keep us warm. Flannel should be worn 
next the skin at all times, except in the heat of summer, 
when cotton flannel may be substitutedo In the coldest 
weather it should be doubledc Its roughness is sometimes 



DISEASES, ETC. 77 

disagreeable, but habit soon overcomes this sensitiveness, 
and renders it exceedingly grateful. Light-colored clotli- 
iiig is not only cooler in summer, but warmer in winter. 
As the warmth of clothing depends very greatly on the 
amount of air contained in its fibres, fine, loose, porous 
cloth with a plenty of nap is best for winter wear. Firm 
and heavy goods are not necessarily the warmest. Furs 
are the very perfection of winter clothing, since they com- 
bine warmth with lightness. Two light woolen garments 
are warmer than one heavy one, as there is betw^een them 
a layer of non-conducting air. All the body except the 
head should be equally protected by clothing. Whatever 
fashion may dictate, no part covered to-day can be un- 
covered to-night or to-morrow, except at the peril of 
health. It is a most barbarous and cruel custom to leave 
the limbs of little children unprotected^ when adults 
would shiver at the very thought of such exposure. 
Equally so is it for children to be thinly clad for the pur- 
pose of hardening them. To go shivering with cold is 
not the way to increase one^s power of endurance. The 
system is made more vigorous by exercise and food; not 
by exposure. In winter there is more fear of too little 
than too much clothing. Above all, the feet need heavy 
shoes with thick soles, and rubbers when it is damp. At 
night, and after exercise, w^e require extra clothing. 

Diseases, etc. — 1. SJ7ysipelas is an inflammation 
(see Inflammation,^. 126) of the skin, and often begins in 
a spot not larger than a pin-head, which spreads with 
great rapidity. It is very commonly checked by the ap- 
plication of a solution of iodine. The burning and con- 
tracting sensation may be relieved by cloths wrung out of 
hot water. 



/8 THE SKIN. 

3. dropsy is a disease in which there is an accumula- 
tion of water in the system. On account of the free pas- 
sage between the cells of the connective tissue, this hquid 
gradually settles into the feet when the person is stand- 
ing ; on reclining, the equilibrium is restored. 

3. Corns are a thickened part of the cuticle, caused by 
pressure or fiiction. They most frequently occur on the 
feet; but are produced on the shoemaker's knee by con- 
stant hammering, and on the soldier's shoulder by the 
rubbing of his musket. This hard portion irritates the 
sensitive cutis beneath, and so causes pain. By soaking 
the feet in hot water, the corn will be softened, when it 
may be pared with a sharp knife. If the cause be re- 
moved, the corn will not return. 

4. In-growi7ig JV^ails are caused by pressure, which 
forces the edge of the toe-nail into the flesh. They may 
be cured by carefully cutting away the part which has 
mal-grown, and then scraping the back of the nail till it 
is thin and no longer resists the pressure. The two por- 
tions, uniting, will draw away the nail from the flesh at 
the edge. They are prevented by paring the nail straight 
across, thus making the corners right angles, and by wear- 
ing broad shoes. 

5. Warts are overgrown papillae. (Fig. 24.) They 
may generally be removed by the apphcation of glacial 
acetic acid, or a drop of nitric acid, repeated until the en- 
tire structure is softened. Care must be taken to keep 
the acid from touching the neighboring skin. The capri- 
cious character of warts has given rise to the popular delu- 
sion concerning the influence of charms upon them. 

6. Chilblain is a local inflammation affecting generally 
the feetj hands, or lobes of the ear. Liability to it gen- 



disi:ases, etc, 79 

erally passes away with manhood. It is not caused by 
'^ freezing the feet/' as many suppose, though attacks are 
brought on or aggravated by exposure to cold and by 
sudden warming. It is subject to daily congestion (see 
Coiiyesiion, page 125), manifested by itching, soreness, etc., 
commonly occurring at night. The best preventive is a 
uniform temperature and careful protection against the 
cold by warm, loose, and plentiful clothing, especially for 
the feet. 

7. Wetis are caused by an unnatural activity of the 
arteries, which deposit more nutriment than is needed. 
Physicians "scatter them,'' as it is termed, by stimulating 
the absorbents to carry off the excess. A boil often disap- 
pears without "coming to a head" in a somewhat similar 
way, i. e., by the renewed activity of the absorbing vessels. 



PRACTICAL QUESTIONS. 

1. If a hair be plucked out, will it grow again ? 

2. What causes the hair to '' stand on end" when we are fright- 
ened? 

3. Why is the skin roughened by riding in the cold 

4. Why is the back of a washer- woman's hand less water-soaked 
than the palm ? 

5. Wliat would be the length of the perspiratory tubes in a single 
square inch of the palm, if placed end to end ? 

6. What colored clothing is best adapted to all seasons? 

7. What is the tflPect of paint and powder on the skin ? 

8. Is water-proof clothing healthful for constant wear? 

9. Why are rubbers cold to the feet ? 

10. Why does the heat seem oppressive when the air is moist ? 

11. Why is friction of the skin invigorating after a cold bath ? 

12. Why does the hair of domestic animals become roughened in 
winter? 



8U PRACTICAL QUESTIONS. 

13. Why do fowls sliake out their feathers erect before they 
perch for the night ? 

14. How can an extensive burn cause death by congestion of the. 
lungs ? 

15. Why do we perspire so profusely after drinking cold water? 

16. What are the best means of preventing skin diseases, colds, 
and rheumatism ? 

17. What causes the difference between the hard hand of a black- 
smith and the soft hand of a woman ? 

18. Why should a painter avoid getting paint on the palm of his 
hand? 

19. Why should we not use the soap or soiled towel at a hotel ? 

20. Which teeth cut like a pair of scissors ? 

21. Which like a chisel ? 

22. Which should be clothed the warmer, a merchant or a 
farmer? 

23. Why should wf. not crack nuts with our teeth ? 

24. Do the edges of the upper and lower teeth meet ? 

25. When fatigued, would you take a cold bath ? 

26. Why is the outer surface of a kid glove finer than the inner ? 

27. Why will a brunette endure the sun's rays better than a 
blonde ? 

28. Does patent-leather form a healthy covering for the feet ? 

29. Why are men more frequently bald than women ? 

30. On what part v)f the head doe^ baldness commonly occur? 
Why? 

31. What does the combination in our teeth of canines and griud- 
ers suggest as to the character of our food ? 

32. Is a staid, formal promenade suitable exercise ? 

33. Is there any danger in changing the warm clothing of oui 
daily wear for the thin one of a party ? 

34. Should we retain our overcoat, shawl, or furs when we come 
into a warm room ? 

35. Which should bathe the oftener, students or out-door laborerr 

36. Is abundant perspiration inj iirious ? 



IV. 

Respiration 



AND 



The Voice. 



*The smooth soft air with pulse-like waves 
Flows murmuring through its hidden caves 
Whose streams of brightening purple rush. 
Fired with a new and livelier blush ; 
While all their burthen of decay 
The ebbing current steals away." 



R 



ESPIRATION 

AND 

The Voice. 



THE organs of Kespiration and the Voice are the 
larynx, the trachea, and the lungs. 

Description of the Organs of Voice. — T/ie Lar- 
ynx, — In the neck is a prominence sometimes called 
Adam^s apple. It is the front of the larynx. This is a 
small triangular box, placed just behind the tongue, and 
at the top of the windpipe. The opening into it from 
the throat is called the glottis, and the cover the epiglottis 
{epi, upon ; glotta, the tongue). The latter is a spoon- 
shaped Ud, which opens when we breathe, but, by a nice 
arrangement, shuts when we try to swallow, and so lets 
our food slip over it into the wsophagus (e-sof -a-gus), the 
tube leading to the stomach. (See Fig. 27.) If we laugh 
or talk when we swallow, our food is apt to "go the wrong 
way," ^. e,, little particles pass into the larynx, and the 
tickling sensation which they produce forces us to cough, 
in order to expel the intruders. 

2%e Vocal Cords.— Ox^ each side of the glottis are 
the so-called vocal cords. They are not really cords, but 



84 RMSFIBATION JL N B THE V I C JBi , 

Fiq. ?7. 




I'assage to the (Esophagus and Windpipe : c, the tongue ; d, the soft p(ua\e. 
mding in g, the uvula ; h, the epiglottis ; i^the glottis ; I, the oesophagus ; i^i\6 
pharynx. ^ 

merely elastic membranes projecting from the sides of the 
box across the opening.* When not in use, they spreed 
apart and leaye a V-shaped orifice (see Fig. 28), through 
which the air passes to and from the lungs. If the cords 
are tightened, the edges approach sometimes within y^^ 
of an inch of each other, and, being thrown into yibration, 
cause corresponding vibrations in the current of air. 
Thus sound is produced in the same manner as by the 

* The cartilages and vocal cords of the larynx may be seen readily in that of 
the ox or sheep. If the flesh be cut off, the cartilages wiU dry and will keop 
for yearSc 



S P S E C H. 



86 




e. By the weal cords ; d, the 
epiglottis. 



vibrations of the tongues of an ^^' ^^■ 

accordeon, or tho strings of a vio- 
lin, only in this case the strings are 
scarcely an inch long. 

DiflFerent Tones of the Voice. 
— The higher tones of the voice are 
produced when the cords are short, 
tight, and closely in contact ; the 
lower, by the opposite conditions. 
Loudness is regulated by the quan- 
tity of air and force of expulsion. 
A falsetto voice is thought to be the 
result of some change in the pharynx (Fig. 27) at the back 
part of the nose. When boys are about fourteen years of 
agC; the larynx enlarges, and the cords grow proportion- 
ately longer and coarser ; hence, the voice becomes deeper, 
or, as we say, " changes.^' 

Speech is voice modulated by the lips, tongue,* palate^ 
and teeth. f It is commonly associated with the voice, but 
is not necessary to it ; for when we whisper we articulate 
the words, although there is no vocalization, i. e., no action 
of the larynx. J 

* The tongue is styled the " nnrnly member," and held responsible for all the 
tattling of the world; but when the tongue is removed, the adjacent organs in 
some way largely supply the deficiency, so that speech is still possible. Huxley 
describes the conversation of a man who had two and one-half inches of his 
tongue preserved in spirits, and yet could converse intelligibly. Only the two 
letters t and d were beyond his power ; hence, tin became '' fin," and dog became 
" thog." 

t An artificial larynx may be made by using elastic bands to represent rhe 
vocal cords, and by placing above them chambers which by their resonarce will 
produce the same efi'ect as the cavities lying above the laiynx. An artificial 
speaking-machine was constructed by Kempelen, which could pronounce such 
sentences as, " I love you with all my heart," in difierent languages, by simply 
touching the proper keys. 

X We can observe this by placing the hand on the throat, and noticing the ab- 
Mnce of yibrations when we whisper, and tkeir presence when we talk. The 



80 



EMB P IMA. TIO. 



jlMB TMM VOICJS. 



Formation of Vocal Sounds. — The method of moa- 
lating voice into speech may be seen by producing the 
pure vowel sounds a, e^ etc.^ from one expiration, the 
mouth being kept open while the form of the aperture ia 
changed for each vowel by the tongue and the hps. H is 
only an explosion, or forcible throwing of a vowel sound 
from the mouth. 

Th© consonants, or short sounds, may also be made 




The Langs, showing the Larynx. 



B, the bronchial tub€9. 



difference between vocalization and n on -vocalization is seen in a Bi?h and R 
groan, the latter belngr the former vocalized. WhiPtllnsr is a pnre month-sound, 
and does not depend on the voice. Laughter is vocal, being the aspirated vow 
els, a, e, or o, convulsively repeatedc 



OMBANS OF RB SFIRATION 



S7 



without interrupting the current of air by various modifi- 
cations of the vocal organs. In sounding singly any one 
of the letters, we can detect its peculiar requirements. 
Thus m and n can be made only by blocking the air in 
the mouth and sending it through the nose ; I lets the air 
escape at the sides of the tongue ; r needs a vibratory 
movement of the tongue; b andj^ stop the breath at the 
lips; d and t, at the back of the palate. Consonants like 
b and d are abrupt, or, like I and s, continuous. Those 
made by the lips are termed labials; those by pressing the 
tongue against the teeth, dentals ; those by the tongue, 
Unguals. 

The child gains speech slowly, Srst learning to pro- 
nounce the vowel a, the consonants b, m, aud p^ and then 
their unions, ba, ma, pa. 

Description of the Or- F?g so 

gans of Respiration. — Be- 
neath the larynx is the wind- 
pipe, or trachea, so called be- 
cause of its roughness. It 
is strengthened by (7-shaped 
cartilages with the openings 
behind, where they are at- 
tached to the oesophagus. 
At the lower end the trachea 
divides into two branches, 
called the right ard left 
bronchi. These subdivide 
into the small bronchial 
tubes, whi-jh ramify through 

the lungs like the branches of a tree, the tiny twigs of 
which at fast end in clusters of cells so small that there 




Bronchial Tubes^ with clmters of celts. 



S8 



RESPIRATION AND THE VOICE. 



are 600,000,000 in all. This cellular structure renders 
the lungs exceedingly soft, elastic, and sponge-like.* The 
stiff, cartilaginous rings so noticeable in the rough sur- 
face of the trachea and the bronchi disappear as we reach 
the smaller bronchial tubes, so that while the former are 
£ept open for the free admission of air, the latter are pro- 




A, the heart; B, the Jungs drawn aside to show the internal organs ; C, the dla^ 
phragm ; D, the liver $ E, the gaU cyst; P, the stomach ; G, the small intestine ; 
H, the transverse colon. 



* The lun^^s of slanghte?e(? aiiimals are vulgarly called " lights," probably on 
account of their lightress. They are similar in structure to those of man. 
They will float on water, and if a small piece be forcibly squeezed between the 
fingers (notice the creaking sound it gives), it will BtiU retain sufacient air to 
make it buoyant. 



BOW wjl' b u e a the. 89 

vided with numerous muscular fibres by which they may 
be opened or closed at will. 

Wrappings of the Lungs. — The lungs are invested 
with a double covering — the pleura — one layer being at- 
tached to the lungs and the other to the walls of the 
chest. It secretes a fluid which lubricates it, so that 
the layers glide upon each other with perfect ease. The 
lungs are lined with mucous membrane, exceedingly deli- 
cate and sensitive to the presence of anything except pure 
air. We have all noticed this when we have breathed any- 
thing offensive. 

The Cilia. — Along the bron- Fig. 32. 

chial tubes are minute hair-like 
bodies {cilia), which are in con- 
stant motion, like a field of grain 
stirred by a gentle breeze. They 
serve to fan the air in the lungs, 
and produce an outward current, 

which is useful in catching dust a, a section of the mucous mem- 
■y n i_' ^ J • T brane, showing the cilia; B, 

and fine particles swept inward rn(yre highZy magnified, 

with the breath. 

How We Breathe. — Respiration consists of two acts- 
taking in the air, or inspiration, and expelling the air, or 
expiration. 

1. Inspiration. — When we draw in a full breath, we 
straighten the spine and throw the head and shoulders 
back, so as to give the greatest advantage to the muscles.* 



* If we examine the bony cage of the thorax or chest in Fig. 8, we shall see 
that the position of the ribs may alter its capacity in two ways. 1. As they run 
obliquely downward from the spine, if the sternum or breast-bone oe lifted in 
front, the diameter of the chest will be increased. 2. The ribs are fastened by 
elastic cartilages, which stretch as the muscles that lift the ribs contract, and bo 
Increase the breadth of tho chest 




00 RESPIRATION AND THE VOICE. 

At the same time the diaphragm* descends and presses 
the walls of the abdomen outward. Both these processes 
increase the size of the chest. Thereupon the elastic 
lungs expand f to occupy the extra space, while the air, 
rushing in through the windpipe, pours along the bron- 
chial tubes and crowds into every cell. 

2. Expiration, — When we forcibly expel the air from 
our lungs, the operation is reversed. We bend forward, 
draw in the walls of the abdomen, and press the dia- 
phragm upward, while the ribs are pulled downward — all 
together diminishing the size of the chest, and forcing the 
air outward. 

Ordinary, quiet breathing is performed mainly by the 
diaphragm — one breath to every four beats of the heart, 
or eighteen per minute. 

Modifications of the Breath. — Sighing is merely a 
prolonged inspiration followed by an audible expiration. 
CougJiing is a violent expiration in which the air is driven 
through the mouth. Sneezing differs from coughing, the 
air being forced through the nose. Snoring is a sleeping 
accompaniment, in which the air passes through both 
nose and mouth. The pecuhar sound is produced by the 

* The diaphragm i8 the muscular partition between the chest and the abdomen. 
It is always convex toward the former and concave toward the latter. (See 
Fig. 31.) Long muscles extend from its centre toward the ribs in front and the 
spine at the back. When these contract, they depress and flatten the diaphragm ; 
when they relax, it becomes convex again. In the former case, the bowels are 
pressed downward and the abdomen pushed outward ; in the latter, the bowels 
spring upward, and the abdomen is drawii inward. 

t It is said that in drawing a full breath, the muscles exert a force equal 
to raising a weight of 750 lbs. When we are about to make a great effort, as 
in striking a heavy blow, we naturally take a deep inspiration, and shut the 
glottis. The confined air makes the chest tense and firm, and enables us to 
exert a greater force. As we let slip the blow, the glottis opens and the air 
escapes, often with a curious aspirated sound, as is noticeable in workmen. 
To make a good shot with a rifle, we should take aim with a fiill chest and 
tight breath, since then the arms will have a steadier support 



TBn; CAPACITY OF THE LUNGS, 91 

palate flapping in this divided current of air, and so throw- 
ing it into vibration. Laughing and crying are very much 
alike. The expression of the face is necessary to distin- 
guish between them. The sounds are produced by short, 
rapid contractions of the diaphragm. Hiccough is con- 
fined to inspiration. It is caused by a contraction of the 
diaphragm and a constriction of the glottis. Yawning, or 
gaping, is like sighing.^ It is distinguished by a wide 
opening of the mouth and a deep, profound inspiration. 
Both processes furnish additional air, and therefore prob- 
ably meet a demand of the system for more oxygen. Fre- 
quently, however, they are, like laughing, sobbing, etc., 
merely a sort of contagion, which runs through an audi- 
ence, and seems almost irresistible. 

The Capacity of the Lungs. — If we take a deep 
inspiration, and then forcibly exhale all the air we can 
expel from the lungs, this amount, which is termed the 
Ircathing capacity, will bear a very close correspondence 
to our stature. For a man of medium height (5 ft. 8 in.) 
it will be about 230 cubic inches,f or a gallon, and for 
each inch of height between five and six feet there wiU be 
an increase of eight cubic inches. — Hutchixso:n'. In 
addition, it is found that the lungs contain about 100 
cubic inches which cannot be expelled, thus making their 
entire contents about 330 cubic inches, or eleven pints. 



♦ Their usefulness lies in bringing? np the arrears, as it were, of respiration, 
when it has ffillen behindhand either through fatigue or close attention to other 
occupation. The stretching of the juws and limbs may also serve to equalize the 
nervous influence, certain muscles having become uneasy on account of being 
stretched or contracted for a long time. 

t Of this amount 100 cubic inches can be forced in only by an extra effort, and 
Is available for emergencies, or for purposes of trainine. as in singing, climbing, 
9tc. It is of great importance, since, if the capacity of the lungs only equale<31 
>ur daily wants, the least obsnruction wjoid prove fataL 



92 RESPIRATION AND THE VOICE. 

The extra amount always on hand in the lungs is of great 
value, since thereby the action of the air goes on continu- 
ously, even during a violent expiration. 

The Need of Air. — The body needs food, clothings 
sunshine, bathing, and drink ; but none of these wants is 
so pressing as that for air. The other demands may be 
met by occasional supplies, but air must be furnished 
every moment or we die. Now the vital element of the 
atmosphere is oxygen gas.* This is a stimulating, life- 
giving principle. No tonic will so invigorate as a few full, 
deep breaths of cold, pure air. Every organ will glow 
with the energy of the fiery oxygen. 

Action of the Air in the Lungs. — In the dehcate 
cells of the lungs the air gives up its oxygen to the blood, 
and receives in turn carbonic acid gas and water, foul 
with waste matter which the blood has picked up in its 
circulation through the body. The blood, thus purified 
and laden with the inspiring oxygen, goes bounding 
through the system, while the air we exhale carries off the 
impurities. In this process the blood changes from purple 
to red, while if we examine our breath we can readily see 
what it has removed from the blood. 

Tests of the Breath. — 1. Breathe into a jar, and 
on lowering into it a lighted candle, the flame will be in- 
stantly extinguished ; thus indicating the presence of car- 
bonic acid gas. 2. Breathe upon a mirror, and a film of 
moisture will show the vapor. 3. If the breath be con- 
fined in a bottle for a time, the animal matter wiU decom- 
pose and give off an offensive odor. 

* See Chemistry^ page 43. The atmosphere consists of one-fifth oxygen and 
four-fifths nitrogen. The former is the active element, and the latter the passive. 
Oxygen alone would be too stimulating, and must be restrained by the neutral 
nitrogep- 



EVIL EFFECT OF R E - B R E A T U I N O . 93 

Our breath is then air robbed of its vitality, and con- 
taining in its place a gas which is as fatal to life * as it is 
to a flame, and effete matter which at the best is disagree- 
able to the smell, injurious to the health, and may contain 
the germs of disease. 

The Evil EflFect of Re-breathing the air cannot be 
over-estimated. We take back into our bodies that which 
has just been rejected. The blood thereupon leaves the 
lungs, bearing, not the invigorating oxygen, but refuse 
matter to obstruct the whole system. We soon feel the 
eifect. The muscles become inactive. The blood stag- 
nates. The heai't acts slowly. The food is undigested. 
Ihe brain is clogged. Instances of fatal results are only 
t(»o frequent, f The constant breathing of even the 
slightly impure air of our houses cannot but tend to 
undermine the health. The blood is not purified, and is 
thus in a condition to receive the seeds of disease at any 
time. X The system uninspired by the energizing oxygen 



^ Carbonic acid gas cannot be breathed when undiluted, as the glottis closes 
aiid forbids its passage into the lungs. Air containing only three or four per 
cent, acts as a narcotic poison (Meller), and a much smaller proportion will 
have an injurious effect. The great danger, however, lies in the organic particles 
constantly exhaled from the lungs and the skin. 

t During the English war in India in the last century, 146 prisoners were shut 
up in a room scarcely large enough to hold them, into which the air could only 
enter by two narrow windows. At the end of eight hours but twenty-three 
remained alive, and these were in a most deplorable condition. This prison was 
well called '' The Black Hole of Calcutta."- Percy relates that after the battle of 
Ansterlitz, 300 Russian prisoners were confined in a cavern, where 260 of them 
perished in a few hours.— The stupid captain of the ship Londonderry, during a 
Btorm at sea, shut the hatches. There were only seven cubic feet of space left 
for each person, and in six hoars ninety of the passengers were dead. 

X The floating dust in the air, revealed to us by the sunbeam shining through 
a crack in the blinds, shows the abundance of these impurities, and also the 
presence of germs which, lodging in the lungs, may implant disease, unless 
thrown off by a vigorous constitution. " On uncovering a scarlet-fever patient, 
a cloud of fine dust is seen to rise from the body— contagious dust, that for days 
will retain its poisonous properties."— Youmans. 



94 RESPIRATION AND THE VOICE. 

is sensitive to cold. The pale cheek, the lustreless eye, 
the languid step, speak but too plainly of oxygen starva- 
tion. In such a soil catarrh, scrofula, and consumption 
run riot.* 

Concerning Ventilation. — The foul air which passes 
off from the lungs and through the pores of the skin does 
not fall to the floor, but diffuses itself through the sur- 
rounding atmosphere. A single breath, therefore, vrill to 
a trifling but certain extent taint the air of a whole room.f 

A light or a fire will vitiate as much air as a dozen per- 
sons. It is now fully established that carbonic oxide ga« 
— a product of combustion still more deadly than carbonic 
acid gas — ^leaks out from a stove through the pores of the 
hot iron. Thus, besides the air which a stove withdraws; 
from a room, it actually poisons that which we breathe. 
Many breaths and lights rapidly unfit the air for our use. 

The perfection of ventilation is reached when the air of 
a room is as pure as that out of doors. To accomplish 
this result it is necessary to allow for each person 800 
cubic feet of space, while ventilation is still going on in, 
the best manner known. ^^ 

In spite of these well-known facts, scarcely any painj- 
are taken to supply fresh air, while the doors and windows 
where the life-giving oxygen might creep in are hermeti- 
cally stopped. 



* ^ One not very strong, or unable powerfally to resist conditions unfavorable 
io health, and with a predisposition to lung disease, will be sure, sooner or later, 
by partial lung-starvation and blood-poisoning, to develop pulmonary consump- 
tion. TTie lack of what is so abundant and so cheap— good, pure air— is unques- 
tionably the one great cause of this terrible diseased— Ten Laws of Health.— 
Black. 

t This grows out of a well-known philosophical principle called the Diffusion 
of Gases, whereby two gases tend to mix in exact proportions, no matter what 
may be the quantity.— C^^wi^^ry, p. 96, and Physics^ p. 49. 



CONCERNING VENTILATION. 93 

Our school-rooms, heated by furnaces or red-hot stoves, 
often have no means of ventilation, or, if provided, they 
are seldom used. A window is occasionally dropped to 
give a little relief, as if pure air were a rarity, and must 
be doled out to the suffering lungs in morsels, instead of 
full and constant draughts. Pupils starved by scanty 
lung-food, and stupefied by foul air, become listless and 
dull. The process goes on year by year. The weakened 
and poisoned body at last succumbs to disease, while we 
in our blindness and ignorance talk of the mysterious 
Providence which thus untimely cuts down the brightest 
intellects. The truth is, death is often simply the penalty 
of violating nature's laws. Bad air begets disease ; disease 
begets death. 

In our churches the foul air left by the congregation on 
Sunday is shut up during the week, and heated for the 
next Lord's day, when the people assemble to re-breathe 
the polluted atmosphere. They are thus forced, with 
every breath they take, to \dolate the physical laws of Him 
whom they meet to worship — laws written not 3000 years 
ago upon Mount Sinai on tables of stone, but to-day en- 
graved in the constitution of their own living, breathing 
bodies. On brains benumbed and starving for oxygen, 
the purest truth and the highest eloquence fall with little 
force. 

We sleep in a bed-room from which every breath of 
fresh air is excluded, because we believe night-air to be 
unhealthy, and so we breathe its half-dozen hogsheads of 
air over and over again, and then wonder why we awaken 
in the morning so dull and unrefreshed ! Eeturn to our 
room after inhahng the fresh, morning air, and the fetid 



96 B JE S F IRATIO N AND THE VOICE 

odor we meet on opening the door will soon convince ua 
how we have poisoned our lungs during the night. 

Each room should be supplied with 2000 feet of fresh 
air per hour for every person it contains. Our ingenuity 
will find some way of doing this most advantageously and 
pleasantly. A moiety of the care we devote to delicate 
articles of food, drink, and dress will abundantly meet this 
prime necessity of our bodies. 

Open the window a little at the top and bottom. Put 
on plenty of clothing to keep warm by day and by night, 
and then let the inspiring oxygen come in as freely as 
God has given it. Pure air is the cheapest necessity and 
luxury of life. Let it not be the rarest ! 

Wonders of Respiration. — The perfection of the 
organs of respiration challenges our admnation. So deli- 
cate are they that the least pressure would cause exquisite 
pain, yet tons of air surge to and fro through their intri- 
cate passages, and bathe their innermost cells. We yearly 
perform at least 7,000,000 acts of breathing, inhaling 
100,000 cubic feet of air, and purifying over 3,500 tons of 
blood. This gigantic process goes on constantly, nevor 
wearies or worries us, and we only wonder at it when 
science reveals to us its magnitude. In addition, by a 
wise economy, the process of respiration is made to sub- 
serve a second use no less important, and the air we exhale, 
passing through the organs of voice, is transformed into 
prayers of faith, songs of hope, and words of social cheer. 

Diseases, etc. — lo Constriction of the JjU7igs is 
produced by tight clothing. The ribs are thus forced in- 
ward, the size of the chest diminished, and the amount of 
inhaled air decreased. A garment which will not admit 
of a iMl breath without inconvenience, anck even stif^ 



DISFAi^£'Sy ETCc 



97 



HlQ. S3. 




A., t?ie natural position of the internal organs. B, wTien deformed by tight lac- 
ing. Marshall says that (he liver arid the stomach have^ in this way^ been forced 
downward almost as low as zhe pehis. 



clothing, will prcTent that free moyement of the ribs so 
essential to health. Any infraction of the laws of respira- 
tion, even though it be fashionable, will result m dimin- 
ished vitality and vigor, and will be fearfully punished by 
sickness and weakness through the whole lifCo 

2. bronchitis is an inflammation (see Inflammation) 
of the mucous membrane of the bronchial tubes. It is ac- 
companied by an increased secretion of mucus, and conse- 
quent coughing. 



98 RESPIRATION AND THE VOICM^ 

3. ^teurisy is an inflammation of the pleura. 1 o is 
sometimes caused by an injury to the ribs, and results in 
a secretion of water within this membrane. 

4. ^neiiinonia {pneuma, breath) is an inflammatioD 
of the lungs, affecting chiefly the air-cells. 

5. Consumption is a disease which destroys the sub 
stance of the lungs. Like other lung difficulties, it is 
caused largely by want of pure air, a liberal supply of 
which is the best treatment that can be prescribed for it.* 

6. dspJijxia (as-fix'-i-a). When a person is drowned, 
strangled, or choked in any way, what is called asphyxia 
occurs. The face turns black ; the veins become turgid ; 
insensibility and often convulsions ensue. If relief is not 
secured within a few minutes, death will be inevitable.f 
(See Appendix.) 

7. ^ip?ii?ie7"ia {diphthera^ a membrane) is a kind of 
sore-throat, in which matter exudes from the mucous 
membrane. This stiffens into a peculiar white substance, 
patches of which may be seen in the back part of the 
mouth. Fever and debility accompany this disease, which 
is so sudden and insidious in its advances as to be exceed- 
ingly dreaded. (See Appendix.) 

8. C7"0iipy which often attacks young children, is an 
inflammation of the mucous membrane of the larynx and 
trachea. It is commonly preceded by a cold. The child 



* *' If I were serionBly ill of consumption, I would live out-doors day and 
night, except in rainy weather or mid-winter ; then I would sleep in an un« 
plastered log-house. Physic has no nutriment, gaspings for air cannot cure you, 
monkey capers in a gymnasium cannot cure you, and stimulants cannot cure 
you. What consumptives want is pure air, not physic — pure air, not medicated 
air— plenty of meat and plenty of bread."— Dr. Marshall Hall. 

t The lack of oxygen, and the presence of carbonic acid gas, are the combined 
causes. Oxygen starvation, and carbonic acid poisoning, each fetal in itself 
work together to destroy life. 



PRACTICAL QUESTIONS, 99 

sneezes, congbs, and is hoarse, but the attack frequently 
comes on suddenly, and usually in the night. It is ac- 
companied by a pecuhar " brassy,^' ringing cough, which, 
once heard, can never be mistaken. It may prove fatal 
within a few hours. (See Appendix.) 

9. SianimeH7ig depends, not on faults of the muscles, 
but on a want of due control of the mind. When a 
stammerer is not too conscious of his lack, and trios to 
form his w^ords slowly, he speaks plainly, and may sing 
well, for then his words must come in time. Many per- 
sons who stutter in common conversation can talk with 
much fluency when making a speech. The stammerer 
should find out his peculiar defect, and overcome it by 
exercise, and especially by speaking only after a full in- 
spiration. 



PRACTICAL QUESTIONS. 

1. What is the philosophy of the " change of voice " in a boy ? 

2. Why can we see our breath on a frosty morning ? 

3. When a law of health and a law of fashion conllict, which 
should we obey ? 

4. If we use a " bunk " bed, should we pack away the clothes 
when we first rise in the morning ? 

5. Why should a clothes-press be well ventilated ? 

6 Should the weight of our clothing hang from the waist or the 
shoulder ? 

7. Describe the effects of living in an over-heated room ? 

8. What habits impair the power of the lungs ? 

9. For full, easy breathing in singing, should we use the dia- 
phragm and lower ribs or the upper ribs alone ? 

10. Why is it better to breathe through the nose than the mouth ? 

11. Wliy should not a speaker talk while returning home on 9 
cold night after a lecture ? 

12. What part of the body needs the loosest clothing \ 

13. What part needs the wannest ? 

LofC. 



100 BEBPIBATIOJS^ AND THE VOIOB. 

14 Why is a " spare bed " generally unhealthfiil ? 
15c Is there any good in sighing ? 

1 6. Should a hat be thoroughly ventilated ? How ? 

17. Why do the lungs of people who live in cities become of a 
gray color ? 

18. How would you convince a person that a bed-room should be 
aired ? 

19. What persons are most liable to scrofula, consumption, etc. ? 

20. If a person is plunged under water, will any enter his lungs ''i 

21. Are bed-curtains healthful ? 

22. Why do some persons take " short breaths " after a meal ? 

23. What is the special value of public parks ? 

24. Can a person become used to bad air, so that it will not injure 
him? 

25. Why do we gape when we are sleepy ? 

26. Is a fashionable waist a model of art in sculpture or painting t 

27. Should a fire-place be closed ? * 

28. Why does embarrassment or fright cause a stammerer to 
stutter still more painfully i 

29. In the organs of voice, what parts have somewhat the sam e 
effect as the case of a violin and the sounding-board of a piano t 

* "Thousands of lives would be saved u all fire-piaces were kept open. If yo-u 

are so fortunate as to have a fire-place in your room, paint it when not in use ; 
put a bouquet of fresh flowers in it every morning, if you please, or do anything 
to make it attractive, but never close it ; better use the fire-boards for kindling- 
wood. It would be scarcely less absurd to take a piece of elegantly tinted court- 
plaster and stop up the nose, trusting to the accidental opening and shutting of 
the mouth for fresh air, because you thought it spoiled the looks of your face to 
have two such great, ugly holes in it, than to stop your fire-place with elegantly- 
tinted paper because it looks better."— Lesds. 



V. 

Circulation 



*No rest this throbbing slave may ask 
For ever quivering o'er his task, 
While far and wide a crimson jet 
Leaps forth to fill the woven net, 
Which in unnumber'd crossing tides 
The flood of burning life divides, 
Then, kindling each decaying part, 
Creeps back to find the throbbing hean/' 

Holmes 



m 




The Circulation. 



THE Organs of the Circulation are the hearty the 
arteries, the veins, and the capillaries. 
The Blood is the hquid by means of which the circn 
lation is eflfected. It permeates every part of the body. 
except the cuticle, nails, hair, etc. The average quantity 

Fig, 35. 





A B 

A, human bloody higMy magnified ; B, t?ie blood of an animal. 

in each person is about eighteen pounds. It is composed 
of a thin, colorless hquidc the plasma, filled with red disks 
or cells,* so small that 3,500 placed side by side would 



♦ Tnere is also one white globular cell to every three or four hundred red ones. 
The "blood is no more red than the water of a stream would he if you were to 



t06 THE CIR aULATION. 

only measure an inch, and it would take 18,000 laid flat- 
wise upon one another to make a column of that height. 
Under the microscope, they are found to be rounded at the 
edge and concave on both sides.* They have a tendency 
to collect in piles like rolls of coin. They vary in size and 
shape in the blood of diflferent animals, f This fact is of 
great value in criminal trials, since blood-stains on gar- 
ments or weapons reveal, under the microscope, whether 
they are from human beings or from animals. J Disks are 
continually forming in the blood, and as constantly dying 
— 20,000,000 at every breath. — Dkapee. The plasma also 

fin it with little red fishes. Suppose the fishes to be very, very small— as small 
as a grain of sand — and closely crowded together through the whole depth of 
the stream ; the water would look quite red, would it not ? And this is the way 
in which blood looks red— only observe one thing ; a grain of sand is a mount- 
ain in comparison with the little red fishes in the blood. If I were to tell you 
they measured about 33V0 of an inch in diameter, you would not be much wiser ; 
BO I prefer saying (by way of giving you a more perfect idea of their minute- 
ness) that there would be about a million in such a drop of blood as would hang 
on the point of a needle. I say so on the authority of a scientific microscopist— 
M. Bouillet. Not that he has ever counted them, as you may suppose, any more 
than I have done ; but this is as near an approach as can be made by calculation 
to the size of s/00 part of an inch in diameter.— Jean Mace. 

* By pricking the end of the finger with a needle, we can obtain a drop for 
examination. Place it on the slide, cover with a glass and put it at once under 
the microscope. The red disks will be seen to group themselves in rows, while 
the white disks will seem to draw apart and to be constantly changing their form. 
Aiter a gradual evaporation, the crystals (Fig. 36) may be seen. In animals they 
have various, though distinctive forms. 

t The following is the size of the cells (corpuscles) in dififerent animals. Cat, 
^Vs of an inch in diameter ; whale, stVo » mouse, ^st* ; liog, -^^^^ ; camel, ^V^ ; 
sheep, -Eizz\ torse, ^J^^; Virginia deer, ^oVe ; dog-faced baboon, s^Vt; brown 
baboon, ^-^^ ; red monkey, ^5 ; black monkey, 35S3 ; perch, ^o^o ; eel, tA^.— 
Gtxlliver's Tables. 

X In one case it is said that the small quantity lodged in the eye of an axe be- 
iween the metal and the wood, although the weapon had been careftuiy cleaned, 
answered for examination and the consequent conviction of the murderer. 
in connection with the statement of tbe text, it should be noticed that recent 
investigations Have thrown great doubt upon the reliabihiy of this test. The 
best microscopists declare that it is impossible to determine accurately whether 
a given specimen of blood is of human or of animal origin. Further research is 
needed fully to settle this point. 



USA'S OF THE BLOOD. 107 

Fig. S6. 




contains fibrin — ^which is merely a solution of lean meat, 
albumen — such as is found nearly pure in the white of an 
egg, and also various mineral substances, as iron,* Ume, 
magnesia, phosphorus, soda, potash, etc. 

Uses of the Blood. — The blood has been called 
" Hquid flesh ;'' but it is more than that, since it contains 
the materials for making every organ. The plasma is 
rich in mineral matter for the bones, and in albumen for 
the muscles. The red disks are the air-cells of the blood. 
They contain the oxygen so essential to every operation 
of life. Wherever there is work to be done or repairs to 
be made, there the oxygen is needed. It stimulates to aa 
tion, and tears down all that is worn out. In this process 
it combines with and actually bums out parts of the mus- 
cles and other tissues, as wood is burned in the stove. 



* Enough iron has been found in the ashes of a burned body k) form a moum< 
ng ring. 



108 THE CIRCULATION, 

The bloody now foul with the l3urned matter, the refuse 
of this fire, is caught up by the circulation and whirled 
back to the lungs, where it is purified, and again sent 
bounding on its way. 

Transfusion. — As the blood is really the ^^ vital fluid/' 
efforts have been made to restore the feeble by infusing 
healthy blood into their veins. If blood be drawn from 
an animal until it is seemingly dead, and then that from 
another animal be injected into its veins, its vitahty will 
be restored.^ This practice became quite common in the 
eeventeenth century. The operation was even tried on 
human beings, and the most extravagant hopes were en- 
tertained. A maniac was restored to reason by the blood 
of a calf. But many fatal accidents occurring, it was for- 
bidden by law, and soon fell into disuse. It has, however, 
been successfully practiced in New York in two or more 
cases within the last two years, and is a method still in 
repute for saving fife. 

Coagulation. — When blood is exposed to the air, it co- 
agulates. This is caused by the hardening of the fibrin, 
which, entangling the red disks, forms the " clot.^' The 
remaining clear, yellow liquid is the serum. The value 
of this peculiar property of the blood can hardly be over- 
estimated. The coagulation soon checks all ordinary cases 
of bleeding, f When a wound is made, and bleeding com- 
mences, the fibrin forms a temporary plug, as it were^ 
which is absorbed when the healing process is finished. J 

* Brown-Sequard tells of a curious instance in which the blood of a living 
log was transferred into one just dead. The animal rose on its feet and wagged 
Its tail, but died a second time twelve and one-half hours afterward. 

t In the case of the lower animals, which have no means of stopping hemor- 
rhages as we have, the coagulation is more rapid, and with insects it is almost 
instantaneous. 

t The fibrin is not an essential ingredient of the blood. All the functions of 



THE HEART. 



109 



Thus we see how a Divine foresight has provided not only 
for the ordinary wants of the body, but also for the ao- 
e\deuts to which it is hable. 

Fig. S7. 




flu Heart, A, the right ventricle ; B, the left ventricle ; C, the right auricle ; 
D, the left auricle. 



The Heart is the engine which propels the blood. It 
IS a hollow, pear-shaped muscle, about the size of the fist. 
It hangs, point downward, just to the left of the centre of 



Hfe are regularly performed in people whose blood lacks fibrin ; and in case? 
of transfusion, where blood deprived of its fibrin was used, the vivifying influ 
ence seemed to be the same. Its office, therefore must mainly be to stanch anT 
hamorrhage which may occur.— Flint. 



110 TEE C IRC L LATI ON. 

the chest. (See Fig. 31.) It is enclosed in a loose sac 
of serous membrane,^ called the pericardium (^m, about; 
and cardia, the heart). This secretes a lubricating fluid, 
and is smooth as satin. 

The Movements of the Heart consist of an alter- 
nate contraction and expansion. The former is called the 
sys'to-le, and the latter the di-as-to4e. During the dias- 
tole the blood flows into the hearty, to be expelled by the 
systole. The alternation of these movements constitutes 
the beating of the heart which we hear so distinctly be- 
tween the fifth and sixth ribs.f 

The Auricles and Ventricles. — The heart is divided 
into four chambers. In an adult, each holds about a 
mne-glassful. The upper ones, from appendages on the 
outside resembling the ears of a dog, are called auricles 
(aureSf ears) ; the lower ones are termed ventricles. The 
auricle and ventricle on each side communicate with each 
other, but the right and left halves of the heart are en- 
tirely distinct, and perform different offices. The left side 



* The mucous mem^brane lines the open cavities of the body, the serous the 
closed. The pericardium is a sac composed of two layers— a fibrous mem- 
brane on the outside, and a serous one on the in3ide. The latter covers the 
external surface of the heart, and is reflected back upon itself in order to form, 
like all the membranes of this nature, a sac without an opening. The heart 
is thus covered by the pericardial sac, but not contained inside its cavity. A 
correct idea may be formed of the disposition of the pericardium around the 
heart by recalling a very common and very convenient, though now discarded 
head-dress, the cotton night-cap. The pericardium encloses the heart exactly as 
this cap covered our forefathers' heads. — Wonders of the Human Body. 

t •' Two sounds are heard if we put our ear over the heart— the first and longer 
as the blood is leaving the organ, the second as it falls into the pockets of the 
two arteries, and the valves then striking together cause it. The first sound is 
mainly the noise made by the muscular tissue. During the first, the two ven- 
tricles contract; during the second, the two auricles do so. The haod may feel 
the heart striking the ribs as it contracts— a feeling called the impulse, or, if 
quicker and stronger than usual, palpitation. This is not always a sign of 
disease, but in hypochondriacs is often an effect of the mind on the nerves 
of the heart."— Mapotheb. 



ikU E IC L E S AND VENTRICLES. Ill 

Fig. S8 




Chambers of the Heart, A, right ventricle ; B, left ventricle ; C, right ateride ; 
O, left auricle; E, tricuspid valve; F, bicuspid valve; G, semi-lunar valves; 
H, valve of the aorta ; I, inferior vena cava ; K, superior vena cava ; L, L, pul- 
monary veins, 

propels the red bloody and the right the dark. The auri- 
cles are merely reservoirs to receive the blood — the left 
auricle, as it filters in bright and pure from the lungs ; the 
right, as it returns dark and foul from the tour of the 
body — and to furnish it to the ventricles as they iieed. 
Their work being so light, their walls are comparatively 
thin and weak. On the other hand, the ventricles force 
the blood — the left, to all parts of the body ; the right, to 
the lungs — and are, therefore, made very strong. As the 
left ventricle drives the blood so much further than the 
right, it is correspondingly thicker and stronger. 

Need of Valves in the Heart. — As the auricles do 
not need to contract with much force simply to empty 



112 



THE CIRCULATION. 

Fig. 39, 




Diagram showing the peculiar Fibrous Structure of the Heart and the Shape of 
the Valves, A, tricuspid valve ; B, bicuspid valve ; C, semi-lunar valves of the 
aorta ; D, semi-lunar valves of the pulmonary artery 

their contents into the yentricles below them, there is no 
necessity for any special contriyance to prevent the blood 
from setting back the wrong way. Indeed, it would natu- 
rally run down into the yentricle, which is at that moment 
open to receiye it. But when the strong yentricles con- 
tract, especially the left one, which must driye the blood 
to the extremities, some arrangement is necessary to pre- 
yent its escaping into the auricle again. Besides, when 
they expand, the "suction power" would tend to draw 
back again from the arteries all the blood just forced out. 
This difficulty is obyiated by means of little doors or 
yalyes, which will not let it go the wrong way.^ 

* The heart of an ox or a sheep may be used to show the chambers and 
valves. The aorta should be cut as far as possible from the heart, and then by 
pumping in water the perfection of these valves will be finely exhibited. Cut 
ting the heart across near the middle will show the greater thickness of the 
left veutricleo 



THE ARTERIES. H^^ 

The Tricuspid and Bicuspid Valves.— At the 

opening into the right ventricle is a valve consisting oi 
three folds or flaps of membrane, whence it is called the 
tricuspid valve (/r^, three; and cuspides, points), and in 
the left ventricle, one containing two flaps, and named 
the M'cuspid valve. These hang so loosely as to oppose 
Qo resistance to the passage of the blood into the ventri- 
cles; but if any attempts to go the other way, it gets be- 
tween the flaps and the walls of the heart, and, driving 
them ontward, closes the orifice. 

These Flaps are Strengthened hke sails by slender 
cords, which prevent their being pressed back through the 
opening. If the cords were attached directly to the walls 
of the heart, they would be loosened in the systole, and so 
become useless when most needed. They are, therefore, 
fastened to little muscular pillars projecting from the sides 
of the ventricle ; when that contracts the pillars contract 
also, and thus the cords are held tight. 

The Semi-lunar Valves. — In the passages out from 
the ventricles are valves, called from their peculiar half- 
moon shape semi-lunar valves {semi, half; Luna, Moon). 
Each consists of three little pocket-shaped folds of mem- 
brane, with their openings in the direction which the 
blood is to take. When it sets back, they fill, and, swell- 
ing out, close the passage. (See Fig. 40.) 

The Arteries * are the tube-like canals which convey 
the blood fi^om the heart to nourish the system. They 
carry only the red blood. (Fig, 34.) They are composed 
of an elastic tissue, which yields at every throb of the 

* Aer^ air ; and terein, to contain— so named because after death they contain 
Air only, and hence the ancients supposed them to be air-tubes leading through 
the body. 



m THE CIRCULATION, 

heart, and then slowly contracting again, keeps up the 
motion of the blood until the next systole. The elasticity 
of the arteries acts hke the air-chamber of a fire-engine, 
which converts the intermittent jerks of the brakes or 
pump into the steady stream of the hose-nozzle. The ar- 
teries communicate with one another by branches or by 
meshes of loops, so that if the blood be blocked in one, it 
can pass round through another, and so get by the obsta- 
cle.* When an artery penetrates a muscle, it is often pro- 
tected by a sheath or by fibrous rings, which prevent its 
being pulled out of place or compressed by the play of the 
muscles. The arteries are generally located as far as pob^ 
Bible beneath the surface, out of harm^s way, and hence 
are found closely hugging the bones or creepiag through 
safe passages provided for them. They are generally nearly 
straight, and take the shortest routes to the parts which 
they are to supply with blood. 

The Arterial System starts from the left ventricle by 
a single trunk — the aorta — which, after giving off branches 
to the head, sweeps back of the chest with a bold curve — 
the arch of the aorta {c, Fig. 34) — and thence runs down- 
ward (/), dividing and subdividing, hke a tree, into 
numberless braixches, which, at last, penetrate every nook 
and corner of the body. 

The Pulse. — At the wrist (^, radial artery) and on the 
^emple (temporal artery) we can feel the expansion of the 
artery by each httle wave of blood set in motion by the 
contraction of the heart. In health, there are about 

* This occurs especially about the joints, where it serves to maintain the cir- 
culation during the bending of a limb, or when the main artery is obstructed by 
disease or injury, or has been tied by the surgeon. In the last case, the small 
adjacent arteries gradually enlarge, and form what is called a collateral circula- 
tion. 



THE VEINS. 115 

seven ty-two* pulsations per minute. They increase with 
excitement or inflammation, weaken with loss of vigor, 
and are modified by nearly every disease. The physician, 
therefore, finds the pulse a good index of the state of the 
system and character of the disorder. 

The Veins are the channels by which the blood re- 
rams to the heart.f They, therefore, caiTy the dark or 
venous blood. As they do not receive the direct impulse 
of the heart, their walls are made much thinner and less 
elastic than those of the arteries. At first small, they in- 
crease in size and diminish in number as they gradually 
empty into one another, like the tiny rills which collect 
to form a river, which, by two mouths, the vena cava 
ascending and vena cava descending (?, m. Fig. 34), empties 
into the right auricle. One set of the veins creep along 
under the skin, where they can be seen, as in the back of 
the hand; another set accompany the arteries, some of 
which have two or more of these satellites. 

Valves similar in construction to those already de- 
scribed (the semi-lunar valves of the heart) are placed at 
convenient intervals, especially in the lower extremities, to 
guide the blood in its course, and prevent its setting back- 
ward.]; We can easily examine the working of these 

• This number varies much with age, sex, and individuals. Napoleon's pulse 
is said to have been only 40, while it is not infrequent to find a healthy pulse 
\t 100 or over. Shame makes the heart send more blood to the blushing 
^heek, and fear almost stops it. The will cannot check the heart. There is said, 
however, to have been a notable exception to this in the case of one Col. Town- 
aend, of Dublin, who, after having succeeded several times in stopping the 
pulsation, at last lost his life in the act. 

t There is one exception to the general course of the veins. The portal vein 
^rries the blood from the digestive organs to the liver, where it is acted upon, 
iience poured into the ascending vena cava, and goes back to the heart. (See 
page 146.) 

X "Too much standing, or tight elastics, often swell and spoil the valves of the 
veins in the leg ; they then become 'varicose, or permanently enlarged, and 
tf they burst, the bleeding may be profuse and even dangerous. Raising 



116 



TME CIRCULATION. 




Valves qftJie Veins. 



calves. On baring the arm, blue veins may be seen run 
aing along the arm toward the hand. Their diameter is 

tolerably even, and they grad* 
^^' ^^' ually decrease in size. If 

now the finger be pressed on 
the upper part of one of 
these veins, and then passed 
downward so as to drive its 
blood backward, swellings 
like little knots will make 
their appearance. Each of these marks the location of a 
valve, which is closed by the blood we push before our finger. 
Remove the pressure, and the valve will swing open, the 
blood set forward, and the vein relapse to its former size. 

The Capillaries (m^^7?^5,ahal^)fo^mafine net- work 
of tubes, connecting the ends of the arteries with the 
veins. They blend, however, with the extremities of these 
two systems, so that it is impossible to tell just where an 
artery ends and a vein begins. So closely are they placed, 
that we cannot prick the flesh with a needle without in- 
juring, perhaps, hundreds of them. The air-cells of the 
blood deposit there their oxygen, and receive carbonic 
acid, while in the delicate capillaries of the lungs f they 

the leg and pressing the finger on the bleeding spot will stay it. Walking 
does not encourage this disease, for the muscles force on the venous blood. 
Clerks who are subject to varicose veins should have seats behind the counters 
where they may rest when not actually employed. A deep breath helps the flow 
in the veins, and a wound may suck in air with fatal effect. A maimed horse is 
most mercifully killed by blowing a bubble of air into the veins of his neck 
As the pressure deep in the sea would burst valves, there are none in the whale, 
and hence a small wound by the harpoon causes him to bleed to death."— 
Mapother. 

t The capillary tubes are there so fine that the disks of the blood have to go 
one by one, and are sadly squeezed at that. However, their elasticity enables 
them to resume their old shape ae soon as they hare escaped from this laby 
rinth. 



TH£ CAPILLARIES. 



117 



Fig. Ul. 




Circulation of the Blood in the Web of a Frog'^s Foot^ highly magnified. A, an 
jrtery ; B, capillaries crowded with disks, owing to a rupture just abme, where th6 
disks are jammed into an adjacent mesh; C, a deeper vein ; the black spots are 
pigment cells. 

give up their load of carbonic acid in exchange for oxygen. 
K, by means of a microscope, we examine the transparent 
web of a frog's foot, we can trace the route of the blood.* 
It is an experiment of wonderful interest. The crimson 
stream, propelled by the heart, rushes through the arte- 
ries, until it reaches the intricate meshes of the capillaries. 
Here it breaks into a thousand tiny rills. We can see the 
disks winding in single file through the deyious passages, 
darting hither and thither, now pausing, swaying to and 
fro with an uncertain motion, and anon dashing ahead, 
until, at last, gathered in the veins, the blood sets steadily 
back on its return to the heart. 

The Circulation f consists of two parts — the lesser 
and the greater. 



* With small splints and twine, a frog's foot can be easily stretched and tied 
80 that the transparent web can be placed on the table of the microscope. 

t The circulation of the blood was discovered by Harvey in 1619. For several 
years he did not dare to publish his belief. When it became known, he was bit- 
terly persecuted, and his praotice as a physician greatly decreased in conse- 



118 



VMS CIRCULATION^ 




Diagram iUustrating the Circulation of the 5 too^?. -Mars hall. A, mna cava 
descending {superior) ; Z, ascending {inferior) ; C, nght auricle ; B right 'ventn- 
de; ^.pulmonary artery; FP, lungs and pulmonary veins; G, left auncle; H, 
left ventricle ; I, K, aorta. 

1. T^e Lesser CirculaHo7i.—'^\^^ dark blood from 
the veins collects in the right auricle, and going through 
the tricuspid valve, empties into the right ventricle. 
Thence it is driven past the semi-lunar valves, through the 
pulmonary artery, to the lungs. After circulating through 
the fine capillaries of the air-cells, it is returned bright 

qnence. He lived, however, to see his theory universally adopted and his name 
honored. Harvey is said to have declared that no man over forty years of age 
accepted his views. 



BEAT OF THE BODY, 119 

aud red, through the pulmonary veins,* to the left 
auricle. 

2. T/ie Greater Circulation, — From the left au- 
ricle, it is forced past the bicuspid valve to the left ventri- 
cle ; thence it is driven through the semi-lunar valves into 
the great aorta, the main trunk of the arterial system 
Passing through the arteries, capillaries, and veins, it re- 
turns through the venae cavae, ascending and descending, 
gathers again in the right auricle, and so completes the 
"grand round" of the body. Both of these circulations 
are going on constantly, as the auricles contract and the 
ventricles expand simultaneously, and vice versa. 

The Velocity of the Blood varies so much in differ- 
ent parts of the body, and is influenced by so many cir- 
cumstances, that it cannot be calculated with any degree 
of accuracy. It has been estimated that a portion of the 
blood will make the tour of the body in about twenty-three 
seconds f (Flikt), and that the entire mass passes through 
the heart in from one to two minutes. J 

Distribution and Regulation of the Heat of the 
Body. — 1. distribution. — The natural temperature is 
not far from 98°. § This is maintained, as we have already 

* It is noticeable that the pahnonary set of veins circulates red blood, and 
the pulmonary set of arteries circulates dark blood. Both are connected with 
the lungs. 

t If a salt which can easily be recognized be inserted in one of the jugnlai 
veins of a dog, and blood be drawn as quickly as possible from the opposite 
jagular, the substance will be detected in from twenty to thirty seconds ; having 
passed to the right heart, thence to the lungs, back to the left heart, through 
the arteries, capillaries, and veins of the face and neck, and into the jugular vein. 

X The total amount of blood in an adult of average weight is about eighteen 
pounds. Dividing this by 5 oz., the quantity discharged by the left ventricle at 
each systole, gives fifty-eight pulsations as the number necessary to transmit all 
the blood in the body. This, however, is an extremely unreliable basis of calcu- 
lation, as the rapidity of the blood is itself so variable. 

§ " The average temperature is, however, easily departed from. Through 



TME CIRGUL ATIO)!r. 

seen, by the action of the oxygen within us. Every oapil 
lary tube is a tiny stove, where oxygen is combining with 
the muscles, tissues, etc., of the body. The heat thus pro- 
duced is distributed by the circulation of the blood. Thus 
the arteries, veins, and capillaries form a series of hot- water 
pipes, through which the heated liquid is forced by a 
pump — the heart — while the heat is kept up, not by a cen- 
tral furnace and boiler, but by a multitude of httle fires 
placed here and there along its course. 

2. ^egzilaiion, — The temperature of the body is regu 
lated by means of the pores of the skin and the mucous 
membrane in the air-passages. When the system becomes 
. too warm, the blood-vessels on the surface expand, the 
blood fills them, the fluid exudes into the perspiratory 
glands, pours out upon the exterior, and by evaporation 
cools the body.* When the temperature of the body is 
too low, the vessels contract, less blood goes to the surface, 
the perspiration decreases, and the loss of heat by evapora- 
tion diminishes, t 

Life by Death. — The body is being incessantly cor- 
roded, and portions borne away by the tireless oxygen. 
The scales of the epidermis are constantly falling off and 



some trivial cause the cooling agencies maybe interfered with, and then, the 
heating processes getting the superiority, a high temperature or fever comes 
on. Or the reverse may ensue. In Asiatic cholera, the constitution of the 
blood is so changed that its disks can no longer carry oxygen into the system, 
the heat-making processes are put a stop to, and, the temperature declining, the 
body becomes of a marble coldness characteristic of that terrible disease." — 
Draper. 
* Just as water sprinkled on the floor cools a room. {Physics^ page 191.) 
t One can go into an oven where bread is baking, or into the arctic regions 
where the mountains are snow and the rivers ice, with equal impunity. Even 
by these extremes the temperature of the blood will be but slightly affected. In 
the one case, the flood-gates of perspiration will be pened and the superfluous 
heat expended in turning the water to vapor ; and in the other, they will be 
^htly closed and all the heat retained. 



WONDERS OF THE HEART, 121 

being replaced by fresh cells from beneath. The disks of 
the blood die, and new ones spring into being. On the 
continuance of this interchange depend our health and 
vigor. Every act is a destructive one. Not a bend of the 
finger, not a wink of the eye, not a thought of the brain 
but is at some expense of the machine itself. Every pro- 
cess of life is thus a process of death. The more rapidly 
this change goes on, and fresh, vigorous tissue takes the 
place of the old, the more elasticity and strength we 
possess. 

Change of our Bodies. — There is a behef that our 
bodies change once in seven years. From the very nature 
of the case, the rate must vary with the labor we perform, 
the organs most used altering offcenest. Probably the 
parts of the body in incessant employment are entirely re- 
organized many times within a single year.* 

The Three Vital Organs. — Death is produced by 
the stoppage of the action of any one of the three organs 
— the heart, the lungs, or the brain. They have, there- 
fore, been termed the " Tripod of Life." Eeally, however, 
as Huxley has remarked, " Life has but two legs to stand 
upon." If respiration and circulation be kept up artifi. 
cially, the removal of the brain will not produce death.f 

Wonders of the Heart. — The ancients thought the 
heart to be the seat of love. There were located the 
purity and goodness as well as the evil passions of the 

* To use a homely simile, our bodies are like the Irishman's knife, which, 
after having had several new blades, and at least one new handle, was yet the 
eame old knife as ever. 

t When death really does take place, i. e., when the vital organs are stopped, 
It is noticeable that the tissues do not die for some time tnereafter. If suitable 
stimulants be applied, as the galvanic battery, transfusion of blood, etc., tlie 
muscles may be made to contract, and many of the phenomena of life ofr 
exhibited- 

a 



122 THE CIRCULATION. 

soul.* Modern science has found the seat of all the men- 
tal powers to be in the brain. But while it has thus 
robbed the heart of its romance, it has rev^ealed wonders 
which eclipse all the mysteries of the past. This marvelous 
little engine throbs on continually at the rate of 100,000 
beats per day, 40,000,000 per year, often 1,000,000,000 
without a single stop. It is the most powerful of ma- 
chines. Its daily work is equal to one-third that of aU the 
muscles, " If it should expend its entire force in lifting 
its own weight vertically, it would rise 20,000 feet in an 
hour.'^ f Its vitality is amazing. Lay upon a table the 
heart from a living sturgeon, aU palpitating with life, and 
it will beat for days as if itself a hving creature. The 
most tireless of organs while life exists, it is one of the last 
to yield when hfe expires. As long as a flutter lingers at 
the heart, we know the spark of being is not quite extin- 
guished, and there is hope of restoration. During a hfe 
such as we sometimes see, it has propelled half a million 
tons of blood, yet repaired itself as it has wasted, during 
its patient, unfaltering labor. The play of its valves and 
the rhythm of its throb have iiever failed until at the com- 
mand of the great Master- Workman the "wheels of life 
have stood still.^^ J 

* Our commor words, hearty, Targe hearted, courage (cor, the heart), are re- 
mains of this fanciful theory. 

t The greatest exploit ever accomplis. .ed by a locomotive, was to lift itself 
through less than one-eighth of that distance. Vast and constant as is this pro- 
cess, so perfect is the machinery that there are persons who do not even know 
where the heart lies until disease or accident reveals its location. 

X " Our brains are seventy-year clocks. The Angel of Life winds them up 
once for all, then closes the case, and gives the key into the hand of the Angel 
of the Resurrection. Tic-tac I tic-tac I go the wheels of thought ; our will can- 
not stop them, they cannot stop themselves ; sleep cannot stop them ; madness 
only makes them go faster ; death alone can break into the case, and, seizing the 
ever-swinging pendulum, whieh we call the heart, silence at last the clicking 
di the terrible escapement we have carried so long beneath our wrinkled fore- 
heads. "— Houses 



TBt. LYMPHATIC C 1 li C U L A T 1 O M l^S 




JOymphatics of the head and neck, showing the glands, and, B, the thoracic d-^ACi 
as it empties into the left innominate vein at the function of the left jugular and 
stibclavian veins. 



The Lymphatic Circulation is intimately connected 
with that of the blood. It is, however, more delicate in 
its organization, and less thoroughly understood. Nearly 
every part of the body is permeated by a second series of 
capillaries, closely interlaced with the blood capillaries al- 
ready described, and termed the Lymphatic system. The 
larger number converge into the thoracic duct — a small 
tube, about the size of a goose-quill, which empties into 
the great veins of the neck. (Fig. 43.) Along their course 
the lymphatics frequently pass through glands — hard, 
pinkish bodies of all sizes, from that of a hemp-seed to an 
almond. These glands are often enlarged by disease, and 
then are easily felt. 

^/^e Ijjmiphy which circulates through the lymphatics 
like blood through the veins, is a thin, colorless liquid, 
very like the ^erumo This fluid, probably in great mee.?^ 



i2Jt 



THE C IBCVh ATIO ^. 



Fig.kk. 





, the leg^ with 
^glands at the hip. 



ure an overflow from the blood- 
vessels, is gathered up by the lym- 
phatics, undergoes in the glands 
some process of preparation not 
well understood, and is then re- 
turned to the circulation. 

Office of the Lymphatics.— 
It is thought that portions of the 
waste matter of the body capable 
of further use are thus, by a wise 
economy, retained and elaborated 
in the system. The lacteals, a 
class of lymphatics which will be 
described hereafter, take up the 
food from the digestive organs and 
fit it for the use of the blood. In 
the lungs the lymphatics are abun- 
dant, absorbing the poison of dis- 
ease, and diffusing it through the 
system.* The lymphatics of the 
skin we have already spoken of as 
producing the phenomena of ab- 
sorption.! Nature in her effort to 
heal a cut deposits an excess of 
matter to fill up the breach. Soon 
the lymphatics go to work and re- 
move the surplus material to other 
parts of the body. Animals which 



* Persons have thus been poisoned by tiny particles of arsenic which evapo 
rate from green wall-paper, and float in the air. 

t Pain is often relieved by infusing under the euticle a solution of morphine 
«^hich is taken up by the absorbents, and so carried through the system 



DISEASES, ETC. 126 

hibernate are supported during the winter by the fat which 
their absorbents carry into the circulation from the extra 
supply they have laid up during the summer. In famine 
or in sickness a man unconsciously consumes his own 
flesh. 

Diseases, etc. — 1. Congestion is an unnatural accu 
luulation of blood in any part of the body. The excess is 
indicated by the redness. If we put our feet in hot water, 
the capillaries will expand by the heat, and the blood set 
that way to fill them. The red nose and purplish face 
of the drunkard show a congestion of the capillaries. 
Those vessels have lost their power of contraction, and so 
are permanently increased in size and filled with blood. 
Blushing is a temporary congestion. The capillaries being 
expanded only for an instant by the nervous excitement, 
contract again and expel the blood.* 



* " Blushing is a purely local modification of the circulation of this kind, and 
it will be instructive to consider how a blush is brought about. An emotion— 
sometimes pleasurable, sometimes painful — takes possession of the mind : there- 
upon a hot flush is felt, the skin grows red, and according to the intensity of the 
emotion these changes are confined to the cheeks only, or extend to the * roots 
of the hair,' or ' all over/ What is the cause of these changes ? The blood is 
a red and a hot fiuid ; the skin reddens and grows hot, because its vessels con. 
tain an increased quantity of this red and hot fluid ; and its vessels contain 
more, because the small arteries suddenly dilate, the natural moderate con- 
traction of their muscles being superseded by a state of relaxation. In othei 
words, the action of the nerves which cause this muscular contraction is sub- 
pended. 

" On the other hand, in many people, extreme terror causes the skin to grow 
cold, and the face to appear pale and pinched. Under these circumstances, in 
fact, the supply of blood to the skin is greatly diminished, in consequence of ap 
excessive stimulation of the nerves of the small arteries, which causes them 
to contract and so to cut off the supply of blood more or less completely. 

"That this is the real state of the case maybe proved experimentally upon 
rabbits. These animals, it is true, do not blush naturally, but they may be made 
to blush artificially. If, in a rabbit, the S3rmpathetic nerve which sends branches 
to the vessels of the head is cut, the ear of the rabbit, which is covered by so 
delicate an integument that the changes in its vessels can be readily perceived, at 
once blushes. That is to say, the vessels dilate, fill with blood, and the ear be^ 
oomes red and hot. The reason of this is, that when the sympathetic nerve is 
f^^nt, the nervous jstirauhis which is ordinarily cent along its branches is int^r 



226 THE CIRCULATION. 

2. InJlammaHon means simply a burning. If there 
is irritation or an injury at any spot, the blood sets thither 
and reddens it. This extra supply, both by its presence 
and the friction of the swiftly moving currents, produces 
beat. The pressure of the distended vessels upon the 
nerves frets them, and produces pain. The swelhng 
stretches the walls of the blood-vessels, and the serum oi 
lymph oozes through. The four characteristics of an in- 
flammation are redness, heat, pain, and swelling. 

3. Steeding ^ if from an artery, will be of red blood, 
and will come in jets ; if from the veins, it will be of dark 
blood, and will flow in a steady stream. K only a small 
vessel be severed, it may be checked by a piece of cloth 
held or bound firmly upon the wound. K a large trunk 
be cut, especially in a limb, make a knot in a handker- 
chief and tie it loosely about the limb ; then, placing the 
knot on the wound, with a short stick twist the handker- 
chief tightly enough to stop the flow.* If you have a 
piece of cloth to use as a pad, the knot will be unneces- 
sary. If you are alone, and are severely wounded, or in 
an emergency, like a railroad accident, use the remedy 
which has saved many a life upon the battle-field ; bind 
or hold a handful of dry earth upon the wound, elevate 
the part, and await surgical assistance. 

rapted, and the muscles of the small vessels, which were slightly contracted, be« 
come altogether relaxed. 

"And now it is quite possible to produce pallor and cold in the rabbit's ear. 
To do this it is only necessary to irritate the cut end of the sympathetic nerve 
which remains connected with the vessels. The nerve then becomes excited, so 
that the muscular fibres of the vessels are thrown into a violent state of contrac- 
tion, which diminishes their calibre so much that the blood can hardly make its 
way through them. Consequently, the ear becomes pale and cold."— Huxley's 
Lessons in Physiology^ page 58. 

* It will, of course, be remembered that if it be an artery which is cut, the 
pressure should be applied between the wound and the heart ; if a vein, beyond 
the wound 



DISEASES, ETC. 121 

4. Sc7*ofuta is generally inherited. It is a disease af- 
fecting the lymphatic glands, most commonly those of the 
neck, forming " kernels," as they are called. It is, how- 
ever, liable to attack any organ, and frequently terminates 
in consumption. Persons inheriting this disease can hope 
to ward off its insidious approaches only by the utmost 
care in diet, exercise, and by the use of pure air and warm 
clothing, avoiding late hours and undue stimulus of all 
kinds. Probably the most fatal and common excitants of 
the latent seeds of scrofula are insufficient or improper 
food and want of ventilation. 

5. A. Cold. — We put on a thinner dress than usual, or, 
when heated, sit in a cool place. The skin is chilled, and 
the perspiration checked. The blood, no longer cleansed, 
and reduced in volume by the drainage through the 
pores, sets to the lungs for purification. That organ is 
oppressed, breathing becomes difficult, and the extra mu- 
cus secreted by the irritated surface of the membrane is 
thrown off by coughing. The mucous membrane of the 
nasal chamber sympathizes with the difficulty, and we 
have " a cold in the head," or a catarrh. In general, the 
excess of blood seeks the weakest point, and develops there 
any latent disease.* Where one person has been killed in 
battle, thousands have died of colds. 

To restore the equipoise must be the object of aU treat- 
ment. We put the feet in hot water and they soon be- 
come red and gorged with the blood which is thus called 

* A party go out for a walk and are caught in a rain, or coming home heated 
from some close aesembly, throw off their coats to enjoy the deliciously cool 
breeze. The next day one has a fever, another a slight headache, another 
pleurisy, another pneumonia, another rheumatism, while some escape without 
any ill feeling whatever. The last had vital force suflacient to withstand the 
disturbance, but in the others there were weak points, and to these the excess 
of blood has gone, producing congestion 



128 



THE CIRCULATION. 



from the congested organs. Hot foot-baths have sayed 
multitudes of lives. It is well in case of a sudden cold to 
go immediately to bed, and with hot drinks and extra 
clothing open the pores, and induce free perspiration. 
This calls the blood to the surface, and by equalizing and 
at the same time diminishing the volume of the circula- 
tion, affords relief.* 

The rule for prevention and cure of a cold is to Tceep the 
Hood upon the surface. 

6. Catarrh most commonly manifests itself by the 
symptoms known as those of a " cold in the head/^ and is 
produced by the same causes. It is an inflammation of the 
mucous membrane lining the nasal and bronchial passages. 
One going out from the hot dry air of a furnace-heated 
room into the cold damp atmosphere of our climate can 
hardly avoid irritating and inflaming this tender mem- 
brane. If our rooms were heated less intensely, and 
ventilated more thoroughly, so that we had not the 
present hot-house sensitiveness to cold air, this disease 
would be far less universal, and perhaps would disappear 
entirely.! 



* Severe colds may often be relieved in their first stages by using lemons 
freely during the day, and taldng at night fifteen or twenty graius of potassium 
bromide. 

t Dr. Gray gives the following table based upon measurement of rooms occu- 
pied by letter-press printers : 





Number percent- 
Spitting Blood. 


Subject to 
Catarrh. 


104 men having less than 500 cubic feet of air to 
breathe 


12.50 


12.50 


115 men having from 500 to 600 cubic feet of air 
to breathe 


4.35 


3.48 


101 men having more than 600 cubic feet of air to 
breathe ..... c . 


3.9€ 


1.98 



PRACTICAL QUESTIONS. 129 



PRACTICAL QUESTIONS. 

I. Why does a dry, cold atmosphere favorably affect catarrh ? 

3. Why should we put on extra covering when we lie down to 
sleep ? 

3. Is it well to throw ofi' our coats or shawls when we come ia 
heated from a long walk ? 

4. Why are close-fitting collars or neck-ties injurious ? 

5. Which side of the heart is the more liable to inflammation / 

6. What gives the toper his red nose ? 

7. Why does not the arm die when the surgeon ties the principal 
Artery leading to it ? 

8. When a fowl is angry, why does its comb redden ? 

9. Why does a fat man endure cold better than a lean one ? 

10. Why does one become thin during a long sickness ? 

II. What would you do if you should come home "wet to the 
skinr' 

12. When the cold air strikes the face, why does it first blanch 
and then flush ? 

13. What must be the effect of tight lacing upon the circulation 
of the blood ? 

14. Do you know the position of the large arteries in the limbs, 
so that in case of accident you could stop the flow of blood ? 

15. When a person is said to be "good-hearted," is it a physical 
truth? 

16. Why does a hot foot-bath relieve the headache ? 

17. Why does the body of a drowned or strangled person turn 
blue? 

18. What are the little *' kernels " in the arm-pits ? 

19. When we are excessively warm, would the thermometer 
show any rise of temperature in the body ? 

20. What forces besides that of the heart aid in propelling the 
blood ? 

21 Why can the pulse be felt best in the wrist ? 

22. Why are starving people exceedingly sensitive to any jar ? 

23. Why will friction, an application of horse-radish leaves, or a 
blister relieve internal congestion ? 

24. Why are students very liable to cold feet ? 

25. Is the proverb that " blood is thicker than water " literally 
true? 

26. What is the effect upon the circulation of "holding the 
breath?" 



130 THE CIRCULATION. 

27. Which side of the heart is the stronger ? 

28. How is the heart itself nourished ? * 

29. Does any venous blood reach the heart without coming through 
the venae cavsB ? 

* The coronary artery, springing from the aorta just after its origin, carries 
olood to the muscular walls of the heart : the venous blood comes back throug-b 
the coronary veins, and empties directly into the right auricle. 



VI. 

Digestion 



AND 



Fo o D. 



A MAN puts some ashes in a hill of com and thereby 
doubles its yield. Then he says, ** My ashes have I turned into 
corn." Weak from his labor, he eats of his corn, and new life 
comes to him. Again, he says, " I have changed my corn into 
a man." This also he feels to be the truth. 

It is the problem of the body, remember, that we are dis- 
cussing. A man is more than the body ; to confound the body 
and the man is worse than confounding the body and the cloth- 
ing. — John Darby. 



Digestion 

AND 

O O D. 



WHY we need Food. — We have learned tntx,t our 
bodies are constantly giving off waste matter — the 
products of the fire or oxidation, as the chemist terms it, 
going on within us. If fresh fuel be not supplied, the fire 
will soon go out. A man without food will starve to death 
in a few days, i. e., the oxygen will have consumed all the 
available flesh of his body.* To replace the daily outgo 
we need about two and a quarter pounds of food, and three 
pounds of drink. (See Appendix, p. 220.) 

With the eight hundred pounds of oxygen taken from 
the air, a man uses in a year about a ton and a half of 



♦ The stories current in the newspapers of persons who live for years wifhoat 
food are, of course, untrue. The recent case of the Welsh Fasting Girl, whict 
excited general interest throughout Great Britain, and was extensively copied 
in our own press, is in point. She had succeeded in deceiving not only the pub- 
lic but, as souie claim, her own parents. At last a strict watch was set by day 
and night, precluding the possibility of her receiving any food except at the 
hands of the committee, from whom she steadily refused it. In a few days she 
died from actual starvation. The youth of the girl, the apparent honesty of the 
parents, and the tragical sequel, make it one of the ^ost remarkable cases of 
the kind on record. 



18^ DIGESTION AND FOODo 

materiaL^ Yet during this entire time his weight may be 
neariy uniform.f Our bodies are but moulds, in which a 
certain quantity of matter, checked for a time on its 
jeaseless round, receives a definite form. They may be 
ikened, says Huxley, to an eddy in the riyer, which re- 
tains its shape for a while, yet every instant each particle 
of water is changing. 

What Food Does. — We make no force ourselves. 
We can only use that which nature provides. J All our 
strength comes from the food we eat. Food is force — 
that is, it contains latent within it a power which it gives 
up when it is decomposed. § Oxygen is the magic key 

* The following is the daily ration of a United States soldier. It is said to be 
the most generous in the world :— 

Bread or flour, 22 ounces. 

Fresh or salt beef (or pork or bacon, 12 oz.), ... 20 " 

Potatoes (three times per week), 16 *' 

Rice, 1-6 " 

Coffee (or tea, 0-24 oz.), , . 1*6 '* 

Sugar, . . . , 2-4 " 

Beans, . . , - 064 gill. 

Vinegar, . , , 0*32 *' 

Salt . , , , 0-16 *' 

t If, however, he were kept on the scale-pan of a sensitive balance, he would 
find that his weight is constantly changing, increasing with each meal, and then 
gradually decreasing. 

X We draw from nature at once our substance, and the force by which we 
operate upon her ; being, so far, parts of her great system, immersed in it for 
a short time and to a small extent. Enfolding us, as it were, within her arms, 
Nature lends us her forces to expend ; we receive them, and pass them on, giv- 
ing them the impress of our will, and bending them to our designs, for a little 

while ; and then Yes ; then it is all one. The great procession pauses not 

Lor flags a moment, for our fall. The powers which Nature lent to us she re- 
sumes to herself, or lends, it may be, to another : the use which we have made 
of them, or might have made and did not, written in her book for eYer.— Health 
and its Conditions. 

§ This force is chemical affinity. It binds together the molecules which com- 
pose the food we eat. When oxygen tears the molecules to pieces and makes 
them up into smaller ones the force is set free. As we shall learn in Philosophy, 
it can be turned into heat, muscular motion, electricity, etc. The principle that 
the different kinds of force can be changed into one another without loss, is 
called the Conservation cf energy, and is one of the grandest discoveries of 
modem science. (See Physics, pages, 37, 40, 208."^ 



riNDS OF FOOD NEEDED. 135 

which unlocks for our use this hidden store. Putting 
food into our bodies is hke placing a tense spring within a 
watch ; every motion of the body is only a new direction 
given to tiiis food-force, as every movement of the hand 
on the dial is but the manifestation of the power of the 
bent spring in the watch. We use the pent-up energies 
of meat, bread, and vegetables w^hich are placed at our 
service, and transfer them to a higher theatre of action.^ 

Kinds of Food Needed. — From what has been said 
it is clear that, in order to produce heat and force, we 
need something that will bum, i. e., with w^hich oxygen 
can combine. Experiment has proved that to build up 
every organ, and keep tne body in the best condition, we 
require three kinds of food. 

1. JVtt7'og 6710218 J^ood^ or that which contains much 
nitrogen. This is a prominent constituent of the tissues 
of the body, and is therefore necessary to their growth 
and repair.f The most common forms are whites of eggs 
— which are nearly pure albumen ; caseine— the chief con« 
stituent of cheese ; lean meat ; and gluten— the viscid sub- 
stance which gives tenacity to dough. Bodies having a 
great deal of nitrogen readily oxidize. Hence the pecuhar 
character of the quick-changing, force-exciting muscle. 

2. Ca7'bo7iaceotis J^ood—\. e., food containing much 
carbon. This consists of two kinds — viz., the sugars and 
t\iQfats. 

(1.) The sugars contain hydrogen and oxygen in the 

* It is a grand thought that we can thus transform what is common and gross 
into the refined and spiritual— that out of waving wheat, wasting flesh, running 
water, and dead minerals, we can realize the glorious possibilities of human 
life. 

t Since this kind of food ^^oeely resembles albumen, it is sometimes called 
AUmminoufi 



186 DIGESTION AND FOOD. 

proportion to form water, and about the same amount of 
carbon. They may, therefore, be considered as water, 
with carbon diflfused through it. In digestion, starch and 
gum are changed to sugar, and so are ranked with this 
class. 

(2.) The fats are hke the sugars in composition, but 
contain less oxygen, and not in the proportion to form 
water. They combine with more oxygen in burning, and 
so giye off more heat. 

The non-nitrogenous elements of the food haye, how- 
ever, other uses than to develop heat."* Fat is essential to 
the formation of every organ, and to the assimilation of 
the food, while sugar and starch aid in digestion, and may 
be converted into fat.t 

3. Mineral Matters. — Food should contain water 
and certain common minerals, such as iron, J sulphur, 
magnesia, phosphorus, salt, and potash. About three 
pints of water are needed daily to dissolve the food and 
carry it through the circulation, to float off waste matter, 
to lubri .-ate the tissues, and by evaporation to cool the 
system. It also enters largely into the composition of the 
body. A man weighing 154 pounds contains 100 pounds 
of water, about 12 gallons — enough, if rightly arranged, to 
drown him. § 

* Tht heat they produce in burning may be turned into motion of the muscle b 
according to the primciple ©f tk© Conservation of energy. (See p. 134, note. 
While ail the structures of the body in their oxidation develop heat, 

t In Turkey the ladies of the harem are fed ©n honey and thick gru^ te make 
Sesh, which is considered t© eohance their beauty.— The negroes on the su^-ar 
pkntations of the South always grow fat during the sugar-making season. 

X While the body can build up a solid from liquid materials on the one 
hand, on the other it can pour iron through its veins and reduce the hardest tex- 
tures to blood.— HZKTON. 

§ It is said that Blumenba^h had a perfect mummy of an adult T^eriflSan, 
which with Mte viscer-a weighed onlv sevea and a half noun-da 



THREE K I X D S OF FOOD, ISl 

Iron goes to the blood disks ; lime combines with phos- 
phoric and carbonic acid to give solidity to the bones and 
teeth ; phosphorus is essential to the activity of the brain. 
Salt is necessary to the secretion of some of the digestive 
fluids, and also to aid in working off from the system its 
waste products. These various minerals, except iron, 
which is sometimes given as a medicine, and salt, univer- 
sally used as a condiment,* are contained in small, but 
suflBcient quantities in meat, bread, and vegetables. 

One Kind of Food is InsuflBcient. — A person fed 
on starch alone, having nothing with which to make 
muscle, would die. It would be a clear case of nitrogen 
starvation. On the other hand, as nitrogenous food con- 
tains carbon, the elements of water, and various mineral 
matters, life could be supported on that alone. But such 
a prodigious quantity of lean meat, for example, would 
be required to furnish the other elements, that not only 



* "Animals will travel long distances to obtain salt. Men will barter gold 
for it ; indeed, among the Gallas and on the coast of Sierra Leone, brothers will 
sell their sisters, husbands their wives, and parents their children for salt. In 
the district of Accra, on the gold coast of Africa, a handful of salt is the most 
valuable thing upon earth after gold, and will purchase a slave or two. Mungo 
Park tells us that with the Mandingoes and Bambaras the use of salt is such a 
luxury that to say of a man, ' he flavors his food with salt,' it is to imply that 
he is rich ; and children will suck a piece of rock-salt as if it were sugar. No 
stronger mark of respect or affection can be shown in Musco^^, than the 
sending of salt from the tables of the rich to their poorer friends. In the 
book of Leviticus it is expressly commanded as one of the ordinances of Moses, 
that every oblation of meat upon the altar shall be seasoned with salt, without 
lacking; and hence it is called the Salt of the Covenant of God. The Gieeks 
and Romans also used salt in their sacrificial cakes ; and it is still used in the 
services of the Latin church— the *• parta mica^ or pinch of salt, being, in the 
ceremony of baptism, put into the child's mouth, while the priest says, 'Receive 
the salt of wisdom, and may it be a propitiation to thee for eternal life.' Every- 
where, and almost always, indeed, it has been regarded as emblematical of wis- 
dom, wit. and immortality. To taste a man's salt, was to be bound by the rites 
of hospitality; and no oath was more solemn than that which was sworn upon 
bread and salt. To sprinkle the meat with salt was to drive away the devil, 
and to this day, nothing is more unlucky than to spill the salt."— Lbthbbt, On 
Food 



138 DIGESTION JlND FOOD. 

would it be yery expensive, but it is likely that after a 
time the labor of digestion would be too onerous, and the 
system would give up the task in despair. The need 
of a diet containing both nitrogenous and carbonaceous 
elements is shown in the fact that even in the tropical 
regions oil is relished as a dressing upon salad. Instinct 
everywhere suggests the blending. Butter is used with 
bread ; rice is boiled with milk ; cheese is eaten with 
maccaroni, and beans are baked with pork. 

The Object of Digestion. — If our food were cast di- 
rectly into the blood, it could not be used. For example, 
although the chemist cannot see wherein the albumen of 
the egg differs from the albumen of the blood, yet if it be 
injected into the veins it is unavailable for the purposes 
required, and is thrown out again. In the course of diges- 
tion the food is modified in various ways whereby it is 
fitted for the use of the body. We call this process as- 
similation — a name for a work done only by the vital 
organs,, and so mysterious in its nature that the wisest 
physiologist only gets glimpses here and there of its oper- 
ations. 

The General Plan of Digestion. — Nature has pro- 
vided for this purpose an entire laboratory, completely 
furnished with a chemist's outfit of knives, mortars, baths, 
chemicals, filters, etc. The food is (1) chewed, mixed 
ivith the saliva in the mouth, and swallowed; (2) it is 
acted upon by the gastric juice in the stomach ; (3) passed 
into the intestines, where it receives the bile, pancreatic 
juice, and other liquids which completely dissolve it ; * 

* "Digestion," says Berzelius, "is a process of rinsing." The digestive ap- 
paratus secretes, and again absorbs with the food which it has dissolved, not less 
than three gallons of liquid per day.— Barnabd, Bidder, Schmidt, and others. 



MASTICATION AND 1 N S A L I V A T 1 O N . 



13ij 



(4) the nourishing part is ab- ^' ^ 

sorbed in the stomach and 
intestines, and thence thrown 
into the blood-vessels, whence 
it is w^hirled through the body , 
by the torrent of the circu- 
lation. These processes take 
place \\4thin the alimentary 
canal, as it is called — a nar- 
row, tortuous tube which com- 
mences at the mouth, and is 
about thirty feet long."^ 

I. Mastication and In- 
salivation. — 1. The Sali- 
va. — The food while being 
cut and ground by the teeth 
is mixed with the sahva. This 
is a thin, colorless, frothy, 
slightly alkaline liquid, se- 
creted f by the mucous mem- 
brane lining the mouth, and 
by three pairs of salivary 
glands (parotid, submaxil- 
lary, and sublingual,) opening into the mouth through 




\pJh 



The Stomach and Intestines. 1, 
sioma<)h ; 2, dvodenum ; 3, smaU in- 
testine ; 4, termination of the Ueum ; 
5, ccBcum ; 6, vermiform appendix; 
7, ascending colon; 8, transverse co- 
lon ; 9, descending colon ; 10. sigmoid 
flexure of the colon ; 11, rectum ; 12, 
spleen — a gland wnme acti&n is not 
understood. 



* The digestive apparatus is lined with mucous membrane, which possesses 
functions similar to those of the outer skin. It absorbs certain subtances and 
rejects waste matter. On account of this clo.^e connection between the innei 
and outer skin, it is not surprising to find that in the lowest animals digestion ig 
performed by means of the external skin. The amieba, which is merely a gelat- 
inous mass, when it takes its food extemporizes a stomach for the occasion. It 
simply wraps itself around the morsel, and like an animated apple-dumpling 
with the apple for food and the crust for animal, goes on with the process until 
the operation is completed, when it unrolls itself again and lets the indigestible 
residue escape. The common hydra of our brooks also does just as well whe» 
turned inside out, like a glove : either side serves eaually for skin or stomach, 

t By secretion la meant merely a separation or picking out from tke bloo<L 



i^ D I & M 8TI0 N AW 3 F B. 




2nt rarom—aneqfmssalkfary glands. 

Incts, or tubes. The amomit varies, bnt on the avera^ 

is about three pounds per clay, and in health is always 
sufficient to keep the mouth moist.* It softens and dis- 
solves the food, and thus enables us to get the flavor oi 
taste of what we eat. It contains a peculiar organic 
principle called ptyaKn,\ which, acting upon the starch 
of the food, changes it into a kind of sugar. 

3. The "Process of Swallowing.— H^^^ food thus 
finely pulverized, softened, and so lubricated by the viscid 
saliva as to prevent all friction as it passes over the deli- 
cate membranes, is conveyed by the tongue and cheek to 

* The presence and often the thought of food will " make one's mouth water." 
Fear checks the flow of saliva, and hence the East Indians sometimes attempt 
to detect theft by making those who are suspected chew rice. The person from 
vhom it comes out driest is adjudged the thief 1 

t One part of ptyalin will convert 8,000 parts of starch into sugar.— Mialhb. 

The saliva has no chemical action on the fats or the albuminous bodies. Its 
irothiness enables it to carry oxygen into the stomach, and this is thought to be 
of service. The action of the ptyalin commences with great promptness, and 
sngar has been detected, it is said, within half a minute after the starch was 
placed in the month. The process, however, is not finished there, but continues 
after reaching the stomach. — Valentin. 

The saliva thus- prepares a small portion of food for absorption at once, and so 
ensures at the very beginning of the operation of digestion a supply of force- 
oroducingf materigl for the immediate use of the system. 



GASTRIC DIGESTION. IJ^l 

the back of the mouth. The soft palate is lifted so as to 
close the nasal opening; the epiglottis shuts down, and 
along this bridge the food is borne, without danger of fall- 
ing into the windpipe or escaping into the nose. The 
muscular bands of the throat now seize it and take it be^ 
yond our control. The fibres of the oesophagus contract 
above, while they are lax below, and convey the food by a 
worm-like motion into the stomach.* 

II. Gastric Digestion. — 1. The Stomach is an ir- 
regular expansion of the digestive tube. Its shape has 
been compared to that of a bagpipe. It holds about three 
pints, though it is susceptible of some distension. It is 
composed of an inner mucous membrane, which secretes 
the digestive fluids ; an outer, smooth, well-lubricated se- 
rous one, which prevents friction, and between them a 
stout, muscular coat. The last consists of two layers of 
longitudinal and circular fibres. When these contract, 
they produce a peculiar churning motion, called the peri- 
staltic {peri, round; stallein, to arrange) movement, which 
thoroughly mixes the contents of the stomach. At the 
further end, the muscular fibres contracting form a gate- 
way, the pylorus (a gate), as it is called, which carefully 
guards the exit, and allows no food to pass from the stom- 
ach until properly prepared, f 

2. The Gasiric Jtiice. — The lining of the stomach 
is soft, velvety, and of a pinkish hue ; but as soon as food 
js admitted, the blood-vessels fill, the surface becomes of a 
bright red, and soon there exudes fi^om the gastric glands 

♦ We can observe the peculiar motion of the cesophagtiB by watching a horse's 
neck when he is drinking. 

t With a wise discretion, however, it opens for buttons, coins, etc., swallowed 
by accident, and when we overload the Btomach it seems to become weary of 
constantly denying egress, and, giving up In despair, lets ererythinjg through. 



lJf!2 DIGESTION ANV FOOD. 

a thin, colorless fluid — the gastric juice. This is secreted 
to the amount of twehe pounds per day.* Its acidity is 
probably due to muriatic or lactic acid — the acid of sour 
milk. It contains a pecuhar organic principle called j^ej^- 
sin\ {pepto, to digest), which acts as a ferment to produce 
changes in the food, without being itself modified. The 
flow of gastric juice is influenced by yarious circum- 
stances. Cold water checks it for a time, and ice for a 
longer period. Anger, fatigue, and anxiety delay and even 
suspend the secretion. The gastric juice has but slight 
effect on the fats or the sugars of the food ; its influence 
being mainly confined to the albuminous bodies, which it 
so changes that they become soluble in water. % 

The food, reduced by the action of the gastric juice to a 
grayish, soupy mass, called chyme (kime), escapes through 
that jealously guarded door, the pylorus. 

III. Intestinal Digestion.— The structure of the in- 
testines is like that of the stomach. There is the same 
smooth, outer, serous membrane to preyent friction, the 
lining of mucous membrane to secrete the digestiye fluids, 
and the muscular coating to push the food forward. The 
intestines are diyided into the small and the large. The 

* The amount secreted by a healthy adult is variously estimated from five to 
thirty-seven pounds. As it is re-absorbed by the blood, there is no loss. 

t Pepsin is prepared and sold as an article of commerce. The best is said to 
De made from the stomachs of young, healthy pigs, which, just before being 
killed, are excited with savory food, which they are not allowed to eat. One 
grain is sufllcient to dissolve 800 grains of coagulated whites of eggs. A temper 
ature of 130° renders pepsin inert. 

X The question is often asked why the stomach itself is not digested by the 
gastric juice, since it belongs to the albuminous substances. Some assign as 
the reason that life protects that organ, and that living tissues cannot be di- 
gested. The fallacy of this has been clearly shown by introducing the legs of . 
live frogs and the ears of rabbits through an opening made in a dog's stomach, 
where they were readily digested. The latest opinion is that the blood which 
circulates so freely through the vessels of "the lining of the stomach, being alk«. 
iBe, protects the tissue against the acidity of the gastric juice. 



tNTM UTIN AL J) J U Ji. S T I If . l^S 



(* 




A Vertical Section of the Duodenum, highly magnified. 1, a fold-like vUhis : 
2, epithelium, or cuticle ; 3, mifices of intestinal glands ; 5, orifice of duodenal 
glands, 4 ; 7, mx)re highly magnified section of the cells of a duodenal gland. 

first part of the former opens out of the stomach, and is 
called the du-o-de -niim^ as its length is equal to the 
breadth of twelve fingers. Here the chyme is acted upon 
bj the Mle and the pancreatic juice. 

1. The !Siie is secreted by the liyer.* This gland 
freighs about four pounds, and is the largest in the body. 
It is located on the right side, below the diaphragm. The 
bile is of a dark, golden color and bitter taste. About 
three pounds are secreted per day. When not needed for 
digestion, it Js stored in the gall cyst.f Its action on the 
food, though not understood, is necessary to life. J 

2. The 'Pa7iC7^eaHc Juice is a secretion of the pan- 
creas, or " sweet-bread " — a gland nearly as large as the 
hand, lying behind the stomach. It is slightly alkaline, 

* Til e liver not only forms the bile otit of the hloocL but elaborates from it 
«rhat is called liver-susrar, and probably also colorless corpuscles : both these 
substances being found in the blood more plentifully after it has passed through 
this ors:an. 

t A gall-bladder can be obtained from a butcher, and the contents kept in a 
bottle for examination. 

X Experiments have been made with animals by opening the gall-bladder and 
Allowing the gall as secreted to flow out of the body without entering the 
gtomach. Flint describes a case where a dog was thus treated. Although 
plentifully fed, he died in thirty-eight days. He suffered no pain, and deat> 
csme grradnally, merely thron9:h a failure r,^ tVo vit?' Dow^rcv 



i^ DIGESTION AND FOOD. 

Fig. hi. 




The Mucous ji±L II LU1 ant ^ ull luuift ^auiuti .itaaiuned. 1^ cellvlar st'moture of 
fhe epiC'elium, or witer lai/er ; 3, a vein ; H, fibrous lai/er ; 4. vi'ii cm^pred with 
epitietium ; 5, a villus in section, showing its lining of epithelium, with its blood- 
vessels and lymphatics ; 6, a villus partially uncovered ; 7, a villus stripped of its 
epithelium ; 8, lymphatics or lacteals ; 9, orifices of the glands opening between, the 
vUli ; 10, 11, 12, glands ; 13, capillaries surrounding the orifijces of the glands. 

and has a ferment^ now called trypsin, haying the power 
of changing starch to sugar. Its main work, however, 
is in breaking up the globules of fat into myriads of 
minute particles, which mix freely with water, and remain 
suspended in it like butter in new milk. The whole mass 
now assumes a milky look, whence it is termed chyle 
(kile), and passes on to the small intestine. 

3. 2'he Small Intestine is an intricately folded tube, 
about twenty-five feet long, and from an inch to an inch 
and three-fourths in diameter. As the chyle passes through 
this tortuous channel, it receives along the entire route 
secretions which seem to combine the action of all the 
previous on^g — itarch, fat, and albumen being affected. 



ABSORPTION, US 

IV. Absorption is performed by the veins, and the 
lacteals, (1.) The Veins in the stomach* immediately 
begin to take up the water, salt, and other substances that 
need no special preparation. In the small intestine, there 
is a multitude of tiny projections {villi) from the folds of 
the mucous membrane, more than 7,000 to the square inch, 
giving it a soft, velvety look. These little rootlets, reach- 
ing out into the milky jBiuid, drink into their minute 
blood-vessels the nutritious part of every sort of food. 
(2.) The Lacteals {lac, milk),f a set of vessels starting in 
the villi side by side with the veins, absorb the principal 
part of the fat. They convey the chyle through the 
lymphatics and the thoracic duct (Fig. 43) to the veins, 
and so mthin the sweep of the circulation. J 

The Portal Vein carries to the liver the food absorbed 
by the veins of the stomach and the villi of the intestine. 
On the way it is greatly modified by the action of the 
blood itself. In the cells of the liver, it undergoes as 
mysterious a process as that performed by the lymphatic 
glands, and is then cast into the circulation. The food, 
potent with force, is now buried in that river of life from 
which the body springs momentarily afresh. 

The Complexity of the process of digestion, as com- 

* The veins of the stomach and the capillaries of the lacteals are separated 
from the food by a thin, moist membrane, through the pores of which the chyme 
and chyle rapidly pass, in accordance with a beautiful law of philosophy (see 
Physics, page 50) called the osmose of liquids. If two liquids of different densi- 
ties are separated by an animal membrane, they will mix with considerable force. 
There is a similar law regulating the interchange of gases through a porous parti- 
tion, in obedience to which the carbonic acid of the blood, and the oxygen of the 
lungs, are exchanged turough the thin membrane of the air-cells. 

t So called because of the milky look given to their contents by the chyle. 

X In this course it is generally modified in its character, and approaches 80 
near the nature of true blood, that if draifn off before it ie emptied into the VfiQi, 
It will Bllghtly coagulate.— HiNTON. * 

7 



H6 DIGESTION AND FOOD. 

pared with the simplicity of respiration and circulation, is 
very marked. The mechanical operation of mastication ; 
the lubrication of the food by mucus ; the provision for 
the security of the respiratory organs; the grasping by 
the muscles of the throat ; the churning movement of the 
stomach ; the guardianship of the pylorus ; the timely in« 
fcroduction by safe and protected channels of the saliva, 
the gastric juice, the bile, the pancreatic juice, and the 
intestinal fluids, each with its special adaptation ; the 
curious peristaltic motion of the intestines ; the twofold 
absorption by the veins and the lacteals ; the final trans- 
formation in the lymphatics, the portal vein, and the 
liver, — all these present a complexity of detail, the neces- 
sity of which can only be explained when we reflect upon 
the variety of the substances we use for food, and the im- 
portance of its thorough preparation before it is allowed to 
enter the blood. 

The Length of Time Required for digesting a full 
meal is from two to four hours. It varies with the kind 
of food, state of the system, perfection of mastication, etc. 
In the celebrated observations made upon Alexis St. Mar- 
tin ^ by Dr. Beaumont, his stomach was found empty in 
two and a half hours after a meal of roast turkey, pota* 
toes, and bread. Pigs' feet and boiled rice were disposed 



* In 1822, Alexis St. Martin, a Canadian to the employ of the American Fur 

Company, was accidentally shot in the If ft side. Two years after, the wound 
was entirely healed, leaving, however, an opening about two and a half inches in 
circumference into the stomach. Through this the mucous membrane protruded, 
forming a kind of valve which prevented the discharge of food but could be 
readily depressed by the finger, thus exposing the interior. For several years 
he was under the care of Dr. Beaumont, a skilful physician, who experimented 
upon him by giving various kinds of food, and watching their digestion through 
this opening. By means of these observations, and others performed on Katii- 
erine Kutt, a woman who had a similar aperture in the stomach, we have Tery 
^TODortant mformatioi? as^to the digestibility of different kinds of faod. 



DIFFERENT KINDS OF FOOD. IJ^I 

of in an hour. Fresh, sweet api)les took one and a half 
hours ; boiled milk, two hours ; and unboiled, a quarter of 
an hour longer. In eggs, which occupied the same time, 
the case was reversed — raw ones being digested sooner 
than cooked. Eoast beef and mutton required three, and 
three and a quarter hours respectively ; veal, salt beef, 
and broiled chicken remained for four hours; and roast 
pork enjoyed the bad pre-eminence of needing five and 
a quarter. 

Value of the DifFerent Kinds of TooA.Seef 
and Mutt07i possess the greatest nutritive value of any 
of the meats. Jjamb is less strengthening, but more 
delicate. Like the young of all animals, it should be 
thoroughly cooked, and at a high temperature, properly to 
develop its delicious flavor. "Poi'k has much carbon, 
and is hence very heating. Those Avho work in the open 
air can dispose of it easily, but the sedentary have little 
need of such food. It sometimes contains a parasite 
called trichina, which may be transferred to the human 
system, producing disease and often death. The only 
preventive is thorough cooking. ^is?i is more watery 
than flesh, but is very like it in composition. Many, how- 
ever, find it difficult of digestion. Like meat, it loses 
its mineral constituents and natural juices when salted, 
and is much less nourishing. Oysters are highly nutri- 
tious, but are more easily assimilated when raw than when 
cooked. 3fitk is a model food, as it contains albumen, 
starch, fat, and mineral matter. No single substance can 
sustain life for so long a time. Clieese is very nourish- 
ing — one pound being equal in value to two of meat, 
but is not adapted to a weak stomach. JEJggs are most 
easily digested when the white is barely coagulated and 



1^ DI& B 8TI0N AND FOOD. 

the yolk is unclianged. :Sread'^ should be made of un- 
bolted flour. The bran of wheat furnishes the mineral 
matter we need in our bones and teeth^ gives the bulk so 
essential to the proper distention of the organs, and by its 
roughness gently stimulates them to action. Corn is rich 
in fat. It contains, however, more indigestible matter 
than any other grain, except oats, and is less nutritious 
than wheat, f The "Potato is two-thirds water— the rest 
being mainly starch, ^ipe jF^7ndtSy and those vegeta- 
bles usually eaten raw, dilute the more concentrated food, 
and also supply the blood with acids, which are cooling 
in summer, and useful, perhaps, in assimilation. 

The Stimulants. — Coffee is about half nitrogen, and 
the rest fatty, saccharine, and mineral substances. It is, 
therefore, of much nutritive value, especially when taken 
with milk and sugar. Its peculiar stimulating property is 
due to a principle called caffeine. Its aroma is developed 
by browning, but destroyed by burning. No other sub-> 
stance so soon relieves the sense of fatigue. J Taken in 



* Very fresh bread, warm "biscuit, etc., are condensed by mastication into a 
pasty mass which is not easily penetrated by the gastric juice, and hence they 
are not healthful. In Germany, bread is not allowed to be sold at the baker's 
till it is twenty-four hours old— a wise provision for those who have not strength 
to resist temptation. This rule of eating may well be adopted by every one who 
cares more for his health than for a gratification of his appetite. 

t Persons unaccustomed to the use of com find it liable to produce derange- 
ment of the digestive organs. This was made fearfully apparent in the prisons 
at Andersonville during the late civil war. The vegetable food of the Federal 
prisoners had hitherto been chiefly wheat-bread and potatoes— the corn bread so 
extensively used at the South being quite new to most of them as a constant 
article of diet. It soon became not only loathsome, but productive of the most 
serious diseases. On the other hand, it was the principal article in the rations 
of the Confederate soldiers, to whom habit made it a nutritious and wholesome 
form of food, as was shown by their endurance. (See Flint's Physiology of 
Man, vol. 2, page 41.) 

X In the late civil war, the first desire of the soldiers upon halting after a 
wearisome march, was to make a cup of coffee. This was taken without milk, 
and often without sugar, yet was always welcome. During Kane's travels iu 



TJSJii STlMULAJSXa. HB 

moderation, it clears the intellect, tranquillizes the nerves, 
and usually leaves no unpleasant reaction. It serves also 
as a kind of negative food, since it retards the process of 
waste. 

In some cases, however, it produces a rush of blood to 
the head, and should be at once discarded. At the close 
of a full meal it hinders digestion, and at night produces 
wakefulness. In youth, when the vital powers are strong, 
and the elasticity of nature prompt in rallying from 
fatigue, it is not needed, and may be injurious in stimula- 
ting a sensitive organization. 

2'ea possesses an active principle called tJieine, Whep 
used moderately, its effects are similar to those of coffee, 
except that it exerts an astringent action. It contains 
tannin, which, if the tea is strong, coagulates the albumep 
of the food — actually tans it — and thus delays digestion.* 

Chocolate contains muon fat, and also nitrogenous 
matter resembling albumen. Its active principle, theohro- 
mine,\ has some of the properties of caffeine and theine. 

Tobacco contains an active principle called nicotine. 
This is so virulent a poison that the amount in one or 
two cigars, if thrown directly into the circulation, would 
cause death. When tobacco is burned, the nicotine enters 
the smoke, and is to some extent absorbed. Its effects 
vary with the habits, constitution, etc., of the individual. 
In many adults it seems to have no injurious influence, 

the Arctic regions, ke found "both tea and coffee te act like a charm, and t© be 
decidedly supeH&r to alcoholic stimulants.'" 

* Tea and coffee should be made with boiling water, but should not be boiled 
afterward. During the " steeping" process, so customary in this country, the 
volatile aroma is lost and a bitter principle extracted. In both England and China 
it is usual to infuse tea directly in the urn from which it is to be drawn. 

t It is said that Linnseus, th« great botanist, was so fond of chocolate that he 
named the cocoa-tree " Theobroma," the food of the gods. 



160 DIGESTION AND FOOD. 

yet it rarely, if ever, does any special good, and all would 
undoubtedly be better without it. Even when the system 
seems to endure the nicotine, symptoms of chronic poison- 
ing often appear after a time. 

Tobacco is always detrimental to youths especially those 
of a nervous, sensitive organization. Its tendency is to 
retard the development of the body. It will, therefore, 
diminish the mental force with which a young man com- 
mences the work of life,^ while its narcotic influence will 
often beguile his energy and palsy his strength at the very 
time when every faculty should be awake. 

Alcohot is the active principle of all fermented liquors. 
Like tobacco, it checks the waste of the body, and so acts 
as a negative food. Contrary to the commonly received 
opinion, it does not fortify against cold. It is a powerful 
stimulant, and often sustains the vital energies when at a 
low ebb, as in sickness, or spurs them when flagging, as in 
old age. It is, therefore, a valuable remedy. So subtle 
and dangerous, however, is its influence on the body (see 
p. 172), and so gi^eat is its liability to abuse, that it should 
rarely be taken except under^ompetent medical advice. 
The indiscriminate use of intoxicating hquors, both as a 
medicine and a beverage, is the curse of society. 

The Cooking of Food breaks the little cells and 
softens the fil )res of which it is composed. In broiling or 
roasting meat, it should be exposed to a strong heat at 
once, in order to coagulate the albumen upon the outside, 
and thus prevent the escape of the nutritious juices. The 

* In the Polytechnic school at Paris, the pupils were divided into two classes— 
the smokers and the non-smokers. The latter not only excelled on the entranc® 
examinations, but daring the entire course of study. Dr. Decaisne examined 
thirty-eight boys who smoked, and found tweiity-&eveii of them dis«^as@d frow 
the use of this poisonous substanoa. 



QUANTITY AND QUALITY OF FOOD, 151 

cooking may then be finished at a lower temperature. 
The same principle applies to boiling meat. In making 
soups, on the contrary, the heat should be applied slowly, 
and should reach the boiling point only for a few moments 
at the close. This prevents the coagulation of the albu- 
men. Frying is an unhealthy mode of cooking food, as 
thereby the fat becomes partially disorganized. 

Rapid Eating produces many evil results. 1. There 
is not enough saliva mixed with the food ; ?. The coarse 
pieces resist the action of the digestive fluids; 3. The 
food is washed down with drinks which dilute the gastric 
juice, and hinder its work ; 4. We do not appreciate the 
quantity we eat until the stomach is overloaded ; 5. Fail- 
ing to get the taste of our food, we think it insipid, and 
hence use condiments which over-stimulate the digestive 
organs. In these various ways the appetite is depraved, 
the stomach vexed, the system overworked, and the foun- 
dations of dyspepsia laid.* 

The Quantity and Quality of Food required vary 
with the age and habits of each individual. The diet of 
a child f should be largely vegetable, and more abundant 
than that of an aged person. A sedentary occupation ne- 
cessitates less food than an out-door life. One accustomed 
to manual labor, on c-utering school, should practice self- 
denial until his system becomes fitted to the new order 
of things. He should not, however, fall into the opposite 
error. We read of great men who have hved on bread and 

* When one is compelled to eat in a hurry, as at a railway station, he would 
do well to confine himself principally to meat ; and to dilute this concentrated 
food with fruit, crackers, etc., taken afterward more leisurely. 

t In youth, repair exceeds waste, and hence the body grows rapidly, and the 
form is plump. In middle life repair and waste equal each other, and growth 
ceases. In old age waste exceeds repair, and hence the powers are enfeebled 
»nd the skin lies ^n wrinkles on the shrunken form 



152 3IQESTI0N A.NJ> F O B . 

water, and the conscientious student sometimes thinks 
that, to be great, he, too, must starve himself.* On the 
contrary, the greatest workers are the greatest eaters. A 
powerful engine needs a corresponding furnace. Only we 
should be careful not to use more fuel than is needed t.o 
run the machine. 

The season should modify our diet. In winter we need 
highly carbonaceous food, plenty of meat, fat, etc. ; but in 
summer we should temper the heat in our corporal stoves 
with fruits and vegetables. 

The climate also has its necessities. The inhabitants 
of the frigid North have an almost insatiable longing for 
fat. Thus, in 1813, when the AlHes entered Paris, the 
Cossacks drank all the oil from the lamps, and left the 
streets in darkness. In tropical regions, a low, unstimU' 
lating diet of fruits forms the chief dependence.! 

When Food should be Taken. — On taking food, 
the blood sets at once to the alimentary canal, and the 
energies are fixed upon the proper performance of this 
work. We should not, therefore, undertake hard study, 
labor, or exercise directly after a hearty meal. We should 
give the stomach at least half an hour. He who toils 
with brain or muscle, and thus centres the blood in any 
particular organ, before eating, should allow time for the 

* As Dr. Holland well remarks, the dispensation of saw-dnst has passed away. 
If we desire a horse to win the race, we must give him plenty of oats. 

t A natural appetite for a particular kind of food is an expression not only of 
desire but of fitness. Thus the craving of childhood for sugar indicates a need 
heat-making food. It is questionable how far it is proper to force or per- 
suade one to eat that which he disrelishes, or his stomach loathes. Life within 
is linked with life without. Each organ requires its peculiar nutriment, and 
there is often a peculiar influence demanded of which we can have no notice 
except by natural instinct Yet, as we are creatures of habit and impulse, we 
need common sense and good judgment to correct the too often wayward 
promptings of an artificial craving. (See page 233.) 



ISrJSISD OF A VARIETY. 16S 

circulation to become e([iialized. There should be an in- 
tei'val of four to live hours between our regular meals, and 
there should be no lunching between times. With young 
children, where the vital processes are more rapid, less 
time should intervene. Nothing should be eaten within 
two or three hours of retiring. 

How Food should be Taken. — A good laugh is the 
best of sauces. The meal-time should be the happiest 
hour of the day. Care and grief are the bitterest foes of 
digestion. A cheerful face and a light heart are friends to 
long hfe, and nowhere do they serve us better than at the 
tab]<,'. God designed that we should enjoy eating, and that, 
h;.^ving stopped before satiety was reached, we should have 
the satisfaction always attendant on a good work w^ell done. 

Need of a Variety. — Careful investigations have 
sliown that any one kind of food, however nutritious in 
itfself, fails after a time to preserve the highest working 
pr)wer of the body. Our appetite palls w^hen w^e confine 
our diet to a regular routine. Nature demands variety, 
and she has furnished the means of gratifying it.* 

The Wonders of Digestion. — We can understand 
n:uch of the process of digestion. We can look into the 
stomach and trace its various steps. Indeed, the chemist 

* " She opens her hand, and pours forth to man the treasures of every land and 
every sea, because she would give to him a wide and vigorous life, participant 
of all variety. For him the cornfields wave their golden grain— wheat, rye, oats, 
maize, or rice, each different, but alike sufficing. Freely for him the palm, the 
dale, the banana, the bread-fruit tree, the pine, spread out a harvest on the air«, 
and pleasant apple, plum, or peach solicit his ready hand. Beneath his foot lie 
-Btored the starch of the potato, the gluten of the turnip, the sugar of the beet ; 
while all the intermediate space is rich with juicy kerbs. 

" Nature bids him eat and be merry : adding to his feast the solid flesh of bird 
and beast, and fish, prepared as victims for the sacrifice : firm muscle to maka 
strong the arm of toil, in the industrious temperate zone ; and mapsire ribs ol 
fat to kindle inward fires for the sad dwellers under Arctic ekies."— £eaZ^A anri 
Us Conditions.— BnnToif 

« 



15i DIGESTION AND FOOD. 

can reproduce in his laboratory many of the operations", 
" a step further/^ as Fontenelle has said, " and he would 
surprise nature in the very act/^ Just here, when he seems 
so successful, he is compelled to pause. At the threshold 
of life the wisest physiologist reverently admires, wonders, 
and worships. How strange is this transformation of food 
to flesh ! We make a meal of meat, yegetables, and diink. 
Ground by the teeth, mixed by the stomach, dissolved by 
the digestive fluids, it is swept through the body. Each 
organ, as it passes, snatches its particular food. Within 
the cells of the tissues^ it is transformed into the soft, 
sensitive brain, or the hard, callous bone ; into briny tears, 
or bland saliva, or acrid perspiration ; bile for digestion, oil 
for the hair, nails for the fingers, and flesh for the cheek- 
Within us is an Almighty Architect, who superintends a 
thousand builders, which make in a way past all human 
comprehension, here a fibre of a muscle, there a filament of 
a nerve ; here constructing a bone, there uniting a tendon — 
fashioning each with scrupulous care and unerring nicety.f 
So, without sound of builder or stroke of hammer, goes up, 
day by day, the body — the glorious temple of the soul. 

Diseases, etc. — 1. 2)yspepsiay or indigestion of 
food, is generally caused by an over-taxing of the digestive 
organs. Too much food is used, and the entire system is 
burdened by the excess. Meals are taken at irregular 

* As the body is composed of individual organs, (see page 19), and each or^n 
of separate tissues (see page 24), so each tissue is made up of minute cells. 
Each cell is a little world by itself, loo small to be seen by the naked eye, but 
open to the microscope. It has its own form and constitution as much as a 
special organ in the body. It absorbs from the blood such food as suits its 
purposes. Moreover the number ol cells in an organ is as constant as the 
number of organs. As the organs expand with the growth of the body, so tha 
cells of each tissue enlarge, but shrink again with age and the decline of life. 
Life begins and ends in a cell.— See Appleton's Cyclopedia, art ''Absorption,'* 

t See Cooke's Bdigion and Chemistry^ page 236. 



PRACTICAL QUESTIONS, iJ^ 

hours, when the fluids are not ready. A hearty supper is 
eaten when the body, wearied with the day^s labor, de- 
mands rest. The appetite craves no food when the diges- 
tion is enfeebled, but stimulants and condiments excite it, 
and the unwilling organs are burdened with that which 
they cannot properly manage. Too great variety of dishes, 
rich food, tempting flavors— all lead to an overloading of 
the stomach. This patient, long-suffering member at last 
wears out. Pain, discomfort, diseases of the digestive or- 
gans, and insufficient nutrition are the penalties of violated 
laws. 

2.' 2'he MiCfnps are a swelling of the parotid — one of 
the salivary glands. (See Fig. 45.) The disease is gene- 
rally epidemic, and the patieiit should be carefully secluded 
for the sake of others as well as himself. The swelling maj 
be allowed to take its course. Eelief from pain is often 
experienced by applying flannels wrung out of hot water. 
Great care should be used not to check the inflammation^ 
and on first going out after recovery, not to take cold. 

PRACTICAL QUESTIONS. 

1. How do clothing and shelter economize food ? 

2. Is it well to take a long walk before breakfast? ' 

3. Why is warm food easier to digest than cold? 

4. Why is salt beef less nutritious than fresh ? * 

5. What should be the food of a man recovering from a fever? 

*Tlie French Academicians found that flesh soaked in -water so as to deprivt^ 
it of its mineral matter and juices, lost its nutritive value, and that animals fed 
on it soon died. Indeed, for all purposes of nutrition, Liebig said it was no bet- 
ter than stones, and the utmost torments of hunger were hardly sufficient to 
induce them to continue the diet. There was plenty of the first class of nutri- 
tive food, but there was no medium for its solution and absorption, and hence it 
was useless. 



166 DIGESTION AND FOOD. 

6. Is a cup of black coffee a healthful oloee to a hearty dinner ? 

7. Should ice-water be used at a meal ? 

8. Why is strong tea or coffee injurious ? 

9. Should food or drink be taken hot ? 

10. Are fruit-cakes, rich pastry, and puddings healthful ? 

11. Why are warm biscuit and bread hard of digestion ? 

12. Should any stimulants be used in youth ? 

13. Why should bread be made spongy ? 

14 Which should remain longer in the mouth, bread or meat ? 

15. Why should cold water be used in making soup, and hot in 
boiling meat ? 

16. Name the injurious effects of over-eating. 

17. Why do not buckwheat cakes, with syrup and butter, taste as 
well in July as in January ? 

18. Why is a late supper injurious? 

19. What makes a man " bilious ? " 

20. What is the best remedy ? Ans. Diet to give the organs rest, 
and active exercise to arouse the secretions and the circulation. 

21. What is the practical use of hunger ? 

22. How can jugglers drink when standing on their heads ? 

23. Why do we relish butter on bread ? 

24. Is chewing tobacco more injurious than smoking ? 

25. Why should ham and sausage be thoroughly cooked ? 

26. Why do we wish butter on fish, eggs with tapioca, oil on 
salad, and milk with rice ? 

27. Explain the relation of food to exercise. 

28. How do you explain the difference in the manner of eating 
between carnivorous and herbivorous animals ? 

29. Why is a child's face plump and an old man's wrinkled ? 

30. Show how life depends on repair and waste. 

31. What is the difference between the decay of the teeth and the 
3onstant decay of the body ? 

32. Should biscuit and cake containing yellow spots of soda be 
eaten ? 

33. Tell how the body is composed of organs, organs are made up 
af tissues, and tissues of cells. 

34. Why do we not need to drink 1 hree pints of water (see page 
133) per day ? 

35. Why, during a pestilence, are those who use liquors as a bev. 
erage the first, and often the only victims ? 

36o What two secretions seem to have the same general use ? 
B7o How may the digestive organs be strengthened ? 



yii. 

Nkrvous System 



"Mark then the cloven sphere that holds 
All thoughts in its mysterious folds, 
That feels sensation's faintest thrill, 
And flashes forth the sovereign will ; 
Think on the stormy world that dwells 
Lock'd in its dim and clustering cells ; 
The lightning gleams of power it sheds 
Along its hollow, glassy threads ! " 



The Nervous System.* 



STRUCTURE. — The neryous system includes the 
Irain, the spmal cord, and the nerves. It is com- 
posed of two kinds of matter — the white and the gray. 
The former consists of milk-white, gUstening fibres, aver- 
aging about J 0^^ Q of an inch in diameter ; the latter, of 
small, ashen-colored cells, forming a pulp-like substance 
of the consistency of blanc-mange. This is often gathered 
in little masses, termed ganglions {ganglion, a knot), be- 
cause, when a nerre passes through a group of the cells, 
they give it the appearance of a knot. The white fibres 
are conductors, while the gray cells are generators of ner- 
yous force.f The ganglia answer to the stations along a 



* The organs of circulation, respiration, and digestion, of which we have 
already spoken, are often called the vegetative functions, because they belong 
also to the vegetable kingdom. Plants have a circulation of sap through their 
cells corresponding to that of the blood through the capillaries. They breathe 
the air through their leaves, which act the part of lungs, and they take in food 
which they change into their own structure by a process which answers to that 
of digestion. The plant, however, is a mere collection of parts incapable of any 
combined action. On the other hand, the animal has a nervous system which 
binds all the organs together. 

t What this force is we do not know. In some respects it is like electricity, 
but, in others, differs materially. Its velocity is abo^t 100 feet per second, f 8ee 
Phyiict, p. 188.) 



160 THE NERVOUS SYSTEM. 

Fig. kB. 




The Nervom System. A, Cerebrum ,' B, CenbeUunu 



THE CEREBRUM. 161 

telegraphic line, where messages are received and trans- 
mitted, and the fibres correspond to the wires which com- 
mnnicate between different parts. 

The Brain is the seat of the mind. Its average weight 
is about fifty ounces.* It is egg-shaped, and fills closely 
the cavity of the skull. It reposes securely on a water- 
bed, being surrounded by a double membrane, delicate as 
a spider's web, which forms a closed sack filled, like the 
spaces in the brain itself, with a liquid resembling water. 
Within this, and closely investing the brain, is a fine tis- 
sue {pia mater), with a mesh of blood-vessels which dips 
down into the hollows, and bathes them so copiously that 
it uses one-fifth of the entire circulation of the body. 
Around the whole is wrapped a tough membrane {dura 
mater), which lines the bony box of the skull, and sepa- 
rates the various parts of the organ by strong partitions. 
The brain consists of two parts — the cerebrum and the 
cerebellum. 

The Cerebrum fills the front and upper part of the 
skull, and comprises about seven-eighths of the entire 
weight of the brain. As animals rise in the scale of life, 
this higher part makes its appearance. It is a mass of 
white fibres, with cells of gray matter sprinkled on the 
outside, or lodged here and there in ganglia. It is so curi- 
ously wrinkled and folded as to strikingly resemble the 
meat of an Enghsh walnut. This structure gives a large 
surface for the gray matter — sometimes as much as 670 
square inches. The convolutions are not noticeable in an 
infant, but increase with the growth of the mind, their 
depth and intricacy being characteristic of high mental 

♦ Ouyier'i brain weighed 64 oz., and that of an idiot only 20 q% 



16S t3:e nervous system^ 




Stiff m$ ^ ihe Om'ibrum. 

power. The cerebrum is divided into two hemisphereSj 
connected beneath by fibres of white matter. Thus we 
have two brains,^ as well as two hands and two eyes. 
This provides us with a surplus of brains, as it were, which 
can be drawn upon in an emergency. A large part of one 
hemisphere has been destroyed without particularly injur^ 



* This donbleness has given rise to some curious speciilatioiis. In the case 
of the hand, eye, etc., we know that the sensation is made more sure. Thus 
we can see with one eye, but not so well as with both. It is perhaps the same 
with the brain. We may sometimes carry on a train of thought, "build an 
air-castle" with one-half of our brain, while the other half looks on and 
watches the operation ; or may read and at the same time think of something 
3lse. So in delirium, a patient often imagines himself two persons, thus showing 
a want of harmony between the two halves. (See Draper's Human Physiology f 
page 329.) 



THE CEREBELLUM, 



163 



ing the mental powers* — just as a person has been blind 
in one eye for a long time without having discovered his 



'^. 50. 




Pigeon from which the G<f/e^rum /mw be4n rmi9V4d. 



The cerebrum is the centre of intelligence and thought. 
Pigeons from which it is removed are plunged in profound 
stupor^ and are inattentive to surrounding objects ; they 
occasionally open their eyes with a vacant stare, and then 
relapse into their former apathy. 

The CerebeUum lies below the cerebrum, and in the 
back part of the head. (See Fig. 48.) It is about the size 
of a small fist. Its structure is similar to that of the brain 
proper, but instead of convolutions it has parallel ridges, 



* A pointed iron bar, three and a half feet long and one inch and a quarter in 
diameter, was driven by the premature blasting of a rock completely through the 
side of the head of a man who was present. It entered below the temple, and 
made its exit at the top of the forehead, just about the middle line. The man 
was at first stunned, and lay in a delirious, semi-stupefied state for about three 
weeks. At the end of sixteen months, however, he was in perfect health, with 
the wounds healed and with the mental and bodily functions unimpaired, except 
that the sight was lost in the eye of the injured side.— Dalton (Note, p. 224.) 




Pigeon from which the Cerebellum has been removed. 

v^^nich, letting the gray matter down deeply into the white 
matter within, give it a peculiar appearance, called the 
arlor-vitce^ or tree of life. (Fig. 54.) This part of the 
brain is the centre for the control of the voluntary mus- 
cles. Persons in whom it is injured or diseased walk as 
if intoxicated, and cannot perform any orderly work. 
Pigeons from which it is removed are excited, nervous, 
and try to escape with uncertain, sprawling movements. 

The Spinal Cord occupies the cavity of the backbone* 
[t is protected by the same membranes as the brain, but^ 
unlike it, the white fibres are on the outside, and the gray 
cells within. Deep fissures separate it into halves (Fig 53)^ 
which are, however, Joined by a bridge of the same sub- 
stance. Just as it starts from the brain, there is an expan- 
sion called the medulla oblongata. (Fig. 54.) 

The Nerves are hard, glistening, silvery threads, com- 
poBed, like the spinal cord, of white matter without a^d 



rMJL^SFUJJx OJf FAIN. 166 

gray within. They ramify to all parts of the body. Often 
they are very near each other, yet are perfectly distinct, 
each conveying its own impression.^ Those which carry 
the orders of the mind to the different organs are called 
the motory nerves ; while those which bring back impres- 
sions which they receive are styled sensory nerves. If 
iie sensory nerve leading to any part be cut, all sensation 
i.n that spot will be lost, while motion will remain ; if the 
motory nerve be cut, all motion will be destroyed, while 
sensation will exist as before. 

Transfer of Pain. — Strictly speaking, pain is not in 
any organ, but in the mind, since only that can feel 
When any nerve brings news to the brain of an injury, 
the mind refers the pain to the end of the nerve. A 
familiar illustration is seen in the " funny bone " behind 
the elbow. Here the nerve {ulnar) gives sensation to the 
third and fourth fingers, in which, if this bone be struck, 
the pain will seem to be. Long after a limb has been 
amputated, pain will be felt in it, as if it still formed a 
part of the body — any injury in the stump being referred 
to the point to which the nerve formerly led. f 



♦ Press two fingers together, and, closing the eyes, let some one pass the 
point of a pin lightly from one to the other ; you will be able to tell which is 
touched, yet if the nerves came in contact with each other anywhere in their 
long route to the brain, you could not thus distinguish. 

t Only about five per cent, of those who suffer amputation lose the feeling of 
the part taken away. There is something tragical, almost ghaptly, in the idea 
of a spirit limb haunting a man through his life, and betraying him in unguarded 
moments into some effort, the failure of which suddenly reminds him of his 
loss. A gallant fellow, who had left an arm at Shiloh, once, when riding, at- 
tempted to use his lost hand to grasp the reins while with the other he struck 
his horse. A terrible fall was the result of his mistake. When the current of 
a battery is applied to the nerves of an arm-stump, the irritation is carried to 
the brain, and referred to all the regions of the lost limb. On one occasion the 
shoulder was thus electrized three inches above the point where the limb was cut 
oflf. For two years the man had ceased to be conscious of his limb. As the 
carrent passed through, i^orant of its possible effects, he started up, crying;, 



166 THE NM RVO US SYSTEM. 

The neryes are divided into three general classes — the 
spinaly the cranialy and the sympathetic 




A, posterior root of a spinal nerve ; fi, ganglion ; B, anterior rootj D, 
spinal nerve. 



The Spinal Nerves, of which there are thirty-on« 
pairs, issue from the spinal cord through apertures pro- 
vided for them in the backbone. Each nerve arises by 
two roots ; the anterior is the motory, and the posterior 
the sensory one. The posterior alone connects directly 
with the gray matter of the cord, and has a small gan- 
glion of gray matter of its own at a little distance from 
its origin. These roots soon unite, i. e., are bound up in 
one sheath, though they preserve their special functions. 
When the posterior root of a nerve is cut, the animal loses 
the power of feehng, and when the anterior root is cut, 
that of motion. If both roots are cut, the part of the 
body supplied by that nerve will become paralyzed, 
motion and feeling being destroyed. 

The Cranial Nerves, twelve pairs m number, spring 
from the lower part of the brain and the medulla oblon- 
gata. 



*• Oh, the hand ! the hand!" and tried to seize it with the living grasp of the 
sound fingers. No resurrection of the dead could have been more startling.— 
Db. Mitchell on " Phantom Lvrribsy Lippinootfs Magazine. 



ItMH CMANIJLL NERVES. 



167 




The Brain and the origin of the twelve pairs of Cranial Nerves. F, E, thi 
cerebrum ; D, the cerebellum^ showing the arbor-vitce ; G, the eye ; H, the meduUa 
oblongata ; A, the spinal cord; C and B, the first two pairs of spinal nerves. 



1. The olfactory y or first pair of nerves, ramify through the nos- 
trils, and are the nerves of smell. 

2. The optic, or second pair of nerves, pass to the eyeballs, and 
are the nerves of vision. 

3. 4, 6. The motores oculi (eye-movers) are three pairs of nerves 
used to move the eyes. 

5. The tri-facial, or fifth pair of nerves, divide each into three 
branches — hence the name : the first to the upper part of the face, 
eyes, and nose ; the second to the upper jaw and teeth ; the third 
to the lower jaw and the mouth, where it forms the nerve of 
taste. These nerves are implicated when we have the toothache or 
neuralgia. 

7. The facial, or seventh pair of nerves, are distributed over the 
face, and give to it expression.* 



* "If it l8 palsied, on one side there will be a blank, while the other side will 
laugh or cry, and the whole face will look funny indeed. There were some cruel 
people in the middle ages who used to cut the nerve and deform children's faces 



168 



THE NERVOUS SYSTEM. 



8. The auditory, or eighth pair of nerves, go to the ears, and are 

the nerves of hearing. 

9. The glos-so-pha-ryn' -ge-al, or ninth pair of nerves, are dis- 
tributed over the mucous membrane of the pharynx, tonsils, etc. 

10. The pneu-mo-gas' -trie, or tenth pair of nerves, preside ovei 
the larynx, lungs, liver, stomach, and one branch extends to the 
heart. This is the only nerve which goes so far from the head. 

11. The accessory y or eleventh pair of nerves, rise from the spinal 
cord, run up to the medulla oblongata, and thence leave the skull 
at the same opening with the ninth and tenth pairs. They regu- 
late the vocal movements of the larynx. 

12. The Jiy-po-glos' -sal, or twelfth pair of nerves, give motion to 

the tongue. 

Fig. 55. 

A 




Spinal Nerces.^ SynviJ^u,^^v.„ 
arcmnd the Internal Organs 
stomach 



K, aorta; A, 



(Ajork 0/ Sympathetic Nervet 
B, diaphragm; C, 



in this way, for tiie purpose of making money of them at shows. When this 
nerve was wrongly supposed to be the seat of neuralgia, or tic-douloureux, it 
was often cut by surgeons. The patient suffered many dangers, and no relief 
of pain was gained,"— Mapother 



REFLEX ACTION, 169 

The Sympathetic System consists of a double chain 
of ganglia on either side of the backbone, extending into 
the chest and abdomen. From these, delicate nerves run 
to the organs on which life depends — the heart, lungs, 
stomach, etc. — to the blood-vessels, and to the spinal and 
cranial nerves over the body. Thus the entire system is 
bound together with cords of sympathy, so that, " if one 
member suffers, all the members suffer with it.^^ 

Here lies the secret of the control exercised by the 
brain over all the vital operations. Every organ responds 
to its changing moods, especially those of respiration, cir- 
culation, digestion, and secretion, — processes intimately 
linked with this system, and controlled by it. 

Crossing of Cords.— Each half of the body is presided 
over, not by its own half of the brain, but that of the op- 
posite side. The nerve fibres, descending from the brain, 
cross each other. When derangement occurs in one half 
of the brain, the opposite half of the body is deprived of 
feeling and motion. The nerves going to the face do not 
thus cross, and therefore the face may be motionless on 
one side, and the limbs on the other. The sensory fibres 
of the spinal nerves also cross, so that an injury to the 
spinal cord may cause a loss of motion in one leg and of 
feeling in the other. 

Reflex Action. — Since the gray matter generates the 
nervous force, a ganglion is capable of receiving an impres- 
sion, and of sending back or reflecting it so as to excite 
the muscles to action. This is done without the con- 
sciousness of the mind.* Thus we wink involuntarily at a 

* Instances of an unconscious working of the mind are abundant. Aber* 
crombie, in his Intellectual Powers^ gives the following : 
" A lawyer had been excesBlvely perplexed about a rery complicated question. 

8 



no THE NERVOUS SYSTEM. 

flash of light or a threatened blow,* We start at a sudden 
sound. We jump back from a precipice before the mind 
has time to reason upon the danger. The spinal cord 
conducts certain impressions to the brain, but responds to 
others without troubling that organ, f The medulla ob- 



An opinion was required from him, but the question was one of such difficulty 
that he felt very uncertain how he should render it. The decision had to 
be given at a certain time, and he awoke in the morning of that day with a 
feeling of great distress. He said to his wife, 'I had a dream, and the whole 
thing was clearly arranged before my mind, and I would give anything to 
recover the train of thought.' His wife said to him, ' Go and look on your 
table.' She had seen him get up in the night and go to his table and sit down 
and write. He did so, and found there the opinion which he had been most 
earnestly endeavoriaig to recover, lying in his own handwriting. There was 
no doubt about it whatever." 

In this case the action of the brain was clearly automatic, i. e., reflex. The 
lawyer had worried his brain by his anxiety, and thus prevented his mind from 
doing its best. But it had received an impulse in a certain direction, and when 
left to itself, worked out the result. (See Questions in Appendix for other illus- 
trations.) 

* " A very eminent chemist a few years ago was making an experiment upon 
some extremely explosive compound which he had discovered. He had a small 
quantity of this compound in a bottle, and was holding it up to the light, looking 
at it intently ; and whether it was a shake of the bottle or the warmth of his 
hand, I do not know, but it exploded in his hand, and the bottle was shivered 
into a million of minute fragments, which were driven in every direction. 
His first impression was, that they had penetrated his eyes, but to his intense 
relief he found presently that they had only struck the outside of his eyelids. 
You may conceive how inflnitesimally short the interval was between the 
explosion of the bottles and the particles reaching his eyes ; and yet in that 
interval the impression had been made upon his sight, the mandate of the 
reflex action, so to speak, had gone forth, the muscles of his eyelids had been 
called into action, and he had closed his eyelids before the particles had reached 
them, and in this manner his eyes were saved. You see what a wonderful proof 
this is of the way in which the automatic action of our nervous apparatus enters 
into the sustenance of our lives, and the protection of om' most important organs 
from injury."— Dr. Carpenter. 

t There is a story told of a man, who having injured his spinal cord, had lost 
feeling and motion in his lower extremities. Dr. John Hunter experimented 
upon him. Tickling his feet, he asked him if he felt it ; the man, pointing to 
his limbs which were kicking vigorously about, answered, " No, but you see my 
legs do." 

Illustrations of this independent action of the spinal cord are common in ani- 
mals. A headless wasp will ply its sting energetically. A fowl, after its head is 
cut off, will flap its wings and jump about as if in pain, although, of course, all 
sensation has ceased. " A water beetle, having had its head removed, remained 
motionless as long as it rested on a dry surface, but when cast into water, it 



CrSES 0^ REFLEX A C T 1 IS . 271 

loij^atd carries on the process of respiration. The great 
sympathetic system binds together all the organs of the 
body. 

Uses of Reflex Action. — We breathe eighteen timea 
every minute ; we stand erect without a consciousness of 
effort ; * we walk, eat, digest, and at the same time carry 
on a train of thought. Our brain is thus emancipated 
from the petty detail of life. If we were obhged to attend 
to every breath, every pulsation of the heart, every wink 
of the eye, our time would be wasted in keeping alive. 
Mere standing would require our entire attention. Be- 
sides, an act which at first demands all our thought soon 
requires less, and at last becomes mechanical, f as we say, 
i. e., reflex. Thus we play a familiar tune upon an instru- 
ment and carry on a conversation at the same time. All 
the possibilities of an education and the power of forming 
habits are based upon this principle. No act we perform 
ends with itself. It leaves behind it in the nervous cen- 
tres a tendency to do the same thing again. Our physical 
being thus conspires to fix upon us the habits of a good or 
an evil life. Our very thoughts are written in our mus- 



executed the usual swimming motions with great energy and rapidity, striking 
all its comrades to one side by its violence, and persisting in these for more than 
half an hour." 

* In this way we account for the perilous feats performed by the somnam- 
bulist. He is not conscious, as his operations are not directed by the cerebrum, 
bai Dy tti« oLhci nervous centres. 

t " As every one knows," says Huxley, " it takes a soldier a long time to learn 
his drill— for instance, to put himself into the attitude of ' attention ' at the in- 
itant the word of command is heard. But, after a time, the sound of the word 
gives rise to the act, whether the soldier be thinking of it or not. There is a 
etory, which is credible enough, though it may not be true, of a practical joker, 
who, seeing a discharged veteran carrying borne his dinner, suddenly called out 
* Attention I' whereupon the man instantly brought his hands down, and lost 
his mutton and potatoes in the gutter. The drill had been thorough, and its 
gfifecte had become embodied in the man's nervous structure." 



172 TBE NEUVOVS SYSTEM. 

cles, so that the expression of our face and even our fear 
tures grow into harmony with the life we liye. 

Brain Exercise.— The nervous system demands its 
life and actiyity. The brain grows by what it feeds on. 
One who reads mainly hght literature, who lolls on the 
Bofa or worries through the platitudes of an idle or a fash- 
lonable hfe, decays mentally ; his system loses tone, and 
physical weakness follows mental poverty. On the other 
hand, an excessive use of the mind withdraws force from 
the body, whose weakness, reacting on the brain, produces 
gradual decay and serious diseases. 

Sleep* is as essential as food. During the day, the pro- 
cess of tearing down goes on ; during the night, the work 
of building up should make good the loss. In youth more 
sleep is needed than in old age, when nature makes few 
permanent repairs, and is content with temporary expe- 
dients. The number of hours required for sleep must be 
decided by each person. Napoleon took only five hours, 
but most people need from six to eight hours — brain- 
workers even more. In general, one should sleep until he 
naturally wakes. If one's rest be broken, it should be 
made up as soon as possible. 

The Effect of Alcohol upon the Nervous Sys- 
tem.— 1. The Stage of ^a^cttement.—T\iQ outposts 
of the nerves are paralyzed. The force, now drawn in to 



* Sleep procured by medicine is rarely as beneficial as that secured naturally, 
■The disturbance to the nervous system is often sufficient to counterbalance all 
ftc good results. Tue Uabit of seeking sleep in this way, without the advice of 
a physician, is to be deprecated. The dose must be constantly increased to pro- 
duce the effect, and thas great injury may be caused. Often, too, where laudanum 
or morphine is used, the person unconsciously comes into a terrible and fatal 
bondage. Especially should infants never be dosed with cordials, as is the com- 
mon family practice. The damage done to helpless childhood by the ignorant 
wad reckless use of soothing syrups is frightftil to contemplate. 



THE EFFECT OF ALCOHOL, 17S 

the nervous centres, drives the machinery of Hfe with tre- 
mendous energy. The heart jumps hke the mainspring 
of a watch when the resistance of the wheels is removed 
The blood surges through the body with increased force. 
Every capillary tube in the system is swollen and flushed, 
like the reddened nose and cheek.* 

2. The Staff e of jyftcscular Weakness. — If the 
influence be still continued, the alcohol acts upon the 
spinal cord. The control of some of the muscles is lost. 
Those of the lower lip usually fail first, then the lower 
Umbs, and the staggering, uncertain steps betray the 
result. The temperature, which for a time was slightly 
increased, soon begins to fall as the heat is radiated, and, 
as the result, the body is cooled. 

3. The Stage of Mental lfeakness.—^\iQ cere- 
brum is now implicated. The centre of thought and 
will being overpowered, the mind is a chaos. The reason 
giving way, the animal instincts assume the mastery of the 
man. The coward shows himself more craven, the brag 
gart more boastful, the bold more daring, and the cruel 
more brutal. At last prostration ensues, and the mid. 
mad revel of the drunkard ends in utter insensibility. 
Fortunately the two nervous centres which supply the 
heart and the diaphragm are the slowest to be influenced. 
So, even in this final stage, the breathing and the circula- 
tion still go on, though the other organs have all stopped. 
Were it not for this, every person thoroughly intoxicated 
would die. In all this, there is stimulation, but no nour- 
ishment, no permanent power conferred on brain or muscle. 



* In time, this condition of the capillaries becomes chronic, and we lee thr 
aifims of It \D tb« red nose and flery fiice of the toner. 



llJf THE NERVOUS SYSTEM. 

"Alcohol may enable a wearied or feeble organism to 
do brisk work for a short time. It may make the brain 
briefly brilliant. It may excite muscle to quick action^ 
but it does nothing at its own cost, fills up nothing it has 
destroyed, and itself leads to destruction.'^ ^ 

Sunlight. — The influence of the sun's rays upon the 
nervous system is yery marked, f It is said also to have 
the effect of developing red disks in the blood. All vigor 
and activity come from the sun. Vegetables grown in 
subdued light have a bleached and faded look. An infant 
kept in absolute darkness would only grow into a shapeless 
idiot. That room is the healthiest to which the sun has 
the freest access. Epidemics frequently attack the in- 
habitants of the shady side of a street, and totally exempt 
those on the sunny side. K, on a slight indisposition, we 
should go out into the opeuk air and bright sunlight, in- 
stead of shutting ourselves up in a close, dark chamber, 
we might avoid many a serious illness. The sun-bath is 
doubtless a most efficient remedy for many diseases. Our 
window blinds and curtains should be thrown back and 
open, and we should let the blessed air and sun stream in 
to invigorate and cheer. No house buried in shade, and 

* The statements given above are based upon the views of Richardson. They 
may be found more fully developed in the Popular Science Monthly for June, 
1872. 

t " The necessity of light for young children is not half appreciated. Many 
of their diseases, and nearly all the cadaverous looks of those brought up in 
great cities, are ascribable to the deficiency of light and air. When we see the 
glass-room of the photographers in ev ^ry street, in the topmost story, we grudge 
them their application to what is often a mere personal vanity. Why should not 
a nursery be constructed in the same manner ? If parents knew the value of 
light to the skin, especially to children of a scrofulous tendency, we should have 
plenty of these glass-house nurseries, where children might run about in a 
proper temperature, free from much of that clothing w^hich at present seals up 
the skin — that great supplementary lung — against sunlight and oxygen. They 
would save many a weakly child who now perishes for lack of these necessaries 
of infant life."— Db. Winthb 



PRACTICAL i^U M; iS Tl u i\ a. Ill, 

no room with darkened wmdows, is fit for human habita- 
tion. In damp and darkness, hes in wait almost every 
disease to which fle;<h is hen*. The sun is their only suc- 
cessful foe. 

Wonders of the Brain.— After having seen the beau- 
tiful contrivances and the exquisite delicacy of the lower 
organs, it is natural to suppose that when we come to the 
brain we should 3nd the most elaborate machinery. How 
surprising, then, it is to have revealed to us only cells and 
fibres! The brain is the least solid and most unsubstan- 
tial looking organ in the body. Eighty per cent, of water, 
si)ven of albumen, some fat, and a few minor substances 
constitute the instrument which rules the world. Strangest 
of all, the brain, which is the seat of sensation, is itself 
without sensation. Every nerve, every part of the spinal 
cord, is keenly alive to the slightest touch, yet " the brain 
may be cut, burned, or electrified without producing pain.^^ 



PRACTICAL QUESTIONS. 

1. Why is ttie pain of incipient hip-disease frequently felt in the 
kuee? 

2. Why does a child require more sleep than an aged person ? 

3. When you put your finger in the palm of a sleeping child, 
why will he grasp it ? 

4. How may we strengthen the brain ? 

5. What is the object of pain ? 

6. Why will a blow on the stomach sometimes stop the heart ? 

7. How long will it take for the brain of a man six feet high U 
receive news of an injury to his foot, and to reply? 

8. How can we grow beautiful ? 

9. Why do intestinal worms ever aifect a child's sight ? 

10. Is there any indication of character in physiognomy ? 

11. When one's finger is burned, where is the ache ? 

12. Is a parlor generally a healthful room ? 



176 THE JS-ERVO US SYSTEM. 

13. Why can an idle scholar read his lesson and at the same time 
count the marbles in his pocket ? 

14. In amputating a limb, what part, when divided, will cause 
the keenest pain ? 

15. What is the effect of bad air on nervous people ? 

16. Is there any truth in the proverb that **he who sleeps, 
dines ? " 

17. What does a high, wide forehead indicate ? 

18. How does indigestion frequently cause a headache ? 

19. What is the cause of the foot's being " asleep ? " * 

20. When an injury to the nose has been remedied by transplant- 
ing skin from the forehead, why is a touch to the former felt in • 
the latter ? 

21. Are closely-curtained windows healthful? 

22. Why,, in falling from a height, do the limbs instinctively take 
a position to defend the important organs ? 

23. What causes the pylorus to open and close at the right time ? 

24. Why is pleasant exercise most beneficial ? 

• 25. Why does grief cause one to lose his appetite ? 

26. Why should we never study directly after dinner ? 

27. What produces the peristaltic movement of the stomach ! 

28. Why is a healthy child so restless and full of mischief? 

29. Why is a slight blow on the back of a rabbit's neck fatal? 

30. Why can one walk and carry on a conversation at the same 
time? 

31. What are the dangers of over-study? 

32. What is the inlluence of idleness upon the brain ? 

33. State the close relation which exists between physical and 
mental health and disease. 

34. In what consists the value of the power of habit ? 

35. How many pairs of nerves supply the eye ? 

36. Describe the reflex actions in reading aloud. 

37. Under what circumstances does paralysis occur ? 

38. If the eye-lids of a profound sleeper were raised, and a candle 
brought near, would the iris contract ? 

39. How does one cough in his sleep ? 

40. Give illustrations of the unconscious action of the brain. 

* " Here the nervous force is prevented from passing "bT compression. Just 
how this is done, or what is kept from passing, we cannot tell. K a current of 
electricity were moving through a rubber tube fall of mercury, a slight squeeze 
would interrupt it. These cases may depend on the same general principle, but 
we cannot assert it."— Huxley. The tingling sensation caused by the compreS' 
mon 73 transf^^rred to the foot, whence the nerve starts. 



VIII. 

Special Senses 



"See how yon beam of seeming white 
Is braided out of seven»hued light ; 
Yet in those lucid globes no ray 
By any chance shall break astray. 
Hark, how the rolling surge of sound, 
Arches and spirals circling round, 
Wakes the hush'd spirit through thine ear 
With music it is heaven to hear." 

Holmes. 



The Special Senses. 



I. TOUCH. 

DESCRIPTION.— Touch is sometimes called the 
" common sense/^ since its nerves are spread over 
the whole body. It is most delicate, however, in the point 
of the tongue and tips of the fingers. The surface of the 
cutis is covered with minute, conical projections called 
papillce,"^ (Fig. 24.) Each of these contains its tiny 
nerve-twigs, which receive the impression and transmit 
it to the brain, where the perception is produced. 

Uses. — Touch is the first of the senses used by a child. 
By it we obtain our idea of sohdity, and throughout life 
rectify all other sensations. Thus, when we see anything 
curious, our first desire is to handle it. 

The sensation of touch is generally relied upon, yet if 
we hold a marble in the manner shown in Fig. 56, it will 
seem like two marbles ; and if we touch the fingers thus 
crossed to our tongue, we shall feel two tongues. Again, 
if we close our eyes and let another person move one of 
our fingers over a plane surface, first lightly, then with 
greater pressure, and then lightly again, we shaU think 
the surface concave. 

* In the palm of the hand, where there are 12,000 In a square inch, we can see 
the fine ridges along which they are arranged. 



180 



THE SPECIAL S'E N S E S . 




This organ is capable of wonderful cultiyation. The 
physician acquires by practice the tactus eruditus,^ or 
learned touch, which is often of great service. The deU- 
cacy of touch possessed by the bhnd almost compensates 
the loss of the absent sense, f 



* An educated sense of touch was possessed by the late Dr. March of Albany, 
to a remarkable degree. It had been cultivated and perfected in the course of 
extensive surgical practice to such an extent as to become delicate, precise, and 
nearly unfailing as a means of diagnosis. On one occasion the Doctor was sum- 
moned to see a man who was supposed to have extensive cancerous disease 
of the thigh, which had been developing many months. The importance of 
the case had called an unusual number of physicians to the bedside of the 
patient, and after very thorough examination of the unyielding swelling by 
them all, Dr. March subjected it to close scrutiny, using his fingers with aston- 
ishing caution and delicacy, and appearing to be absorbed in the investigation. 
A consultation followed in an adjoining room, and from the youngest to the 
oldest, opinions were expressed that the tumor was malignant in character and 
called for amputation of the thigh, as affording the only means of arresting the 
disease, or of saving or prolonging life. Dr. March dissented from this view, 
and boldly stated that the swelling was an abscess, which could be emptied by 
a free incision. The reputation of the surgeon, and the positiveness of his as- 
sertion, caused his advice to be heeded, and he was permitted to make an 
attempt to reach the matter, under mental protest of his associates that he would 
fail in his expectations. The patient, willing to believe almost against hope, 
suffered the Doctor to proceed with the operation. Taking a scalpel, and guided 
by his fingers in selecting a location, he made a deep incision through the dense 
structures of the thigh. Nothing but blood flowed from the wound. A second 
plunge of the knife brought such an overwhelming discharge of pus from the 
immensely-distended cavity, as to amount in the quantity collected to several 
pints. Rapid recovery followed and the limb was saved.— Wm. C. Wet. 

t The sympathy between the difl"erent organs shows how they all combine to 
make a home for the mind. When one sense fails, the others endeavor to 
remedy the defect. It is touching to see how the blind man gets along without 
eyes, and the deaf without ears. Cuthbert, though blind, was the most efficient 
polisher of telescopic mirrors in London. Baunderson, the suocesBor of Newton 



TASTH. 



181 



II. TASTE. 

Fig. 67. 




The Tongue, showing the three kinds of PapUlce—the conical (D), the wkip-likt 
(K, I), the drcumvaUate or entrenched (H, L); E, F, G, nerves; C, glottis. - 
Lankeste«. 

Description. — This sense is located in the papillae oi 
the tongue and palate. These papillae start up when tast- 
ing, as you can see by placing a drop of vinegar on another 

as professor of mathematics at Cambridge, could distinguish between real and 
spurious medals. There is an instance recorded of a blind man who could 
recognize colors. The author knew one who could tell when he was approaching 
a tree, as he said, by the different feeling of the air. 



182 THE SPECIAL SENSES. 

person^s tongue, or your own, before a mirron The vel- 
vety look of this organ is given by hair-hke projections of 
the cuticle upon some of the papillae. They absorb the 
liquid to be tasted, and convey it to the nerves.* The 
back of the tongue is most sensitive to salt and bitter 
substances, and as this part is supplied by the ninth paii 
of nerves (Fig. 54), which is in sympathy with the stomach, 
such flavors often produce vomiting. The edges of the 
tongue are most sensitive to sweet and sour substances, 
and as this part is supplied by the fifth pair of nerves, 
which also goes to the face, an acid, by sympathy, distorts 
the countenance. 

The Use of the Taste was originally to guide in tbs 
selection of food ; but it has become so depraved by cond> 
ments and the force of habit that it would be a difficult 
task to tell what are one's natural tastes. 



III. SMELL.f 

Description. — The nose, the seat of this sense, is com^ 
posed of cartilage covered with muscles and skin, and 
joined to the skull by small bones. The nostrils open at 
the back into the pharynx, and are hned by a continua- 
tion of the mucous membrane of the throat. The olfac- 
tory nerves (first pair, Fig. 54) enter through a sieve-like, 
bony plate at the roof of the nose, and are distributed 
over the inner surface of the two olfactory chambers. 

* Ao insoluble substance is therefore tasteless. 

t The sense of smell is so intimately connected with that of taste that we often 
fail to distinguish between them. Garlic, vanilla, coffee, and various spices, 
which seem to have such distinct taste, have really a powerful odor but a 
feeble flavor. 



aMM LL. 



iSS 



The object to be smelled need not touch the nose, but 
tiny particles borne on the air enter the nasal passages.* 



Fig. 58. 




A, t), C, d, interior of the yiose., which is lined by a mucous membraite ; n, U^ 
nosp : e, the wing of the nose ; q, the nose-hones ; o, the upper lip ; g, section of tM 
upj)er jaw-bone ; ii, the upper part of the mouth, or hard palate ; m, frontal bone 
of the skuU ; k, the ganglion or bulb of the olfactory nerve in the skuU^from which 
o.re seen the branches of the nerve passing in all directions. 



* " Three-quarters of a grain of musk placed in a room cause a very powerful 
smell for a considerable length of time without any sensible diminution in 
weight, and the box in which musk has been placed retains the perfume for 
almost an indefinite period. Haller relates that some papers which had been 
perfomed by a grain of ambergris, were still very odoriferous after a L pse of 
forty years. 

" Odors are transported by the air to a considerable distance. A dog recog- 
ttiaes his master's approach by smell even when he is far away; and we are 
assured by navigators that the winds bring the delicious odors of the balmy 
forests of Ceyloa to a distance of ten leagues from the coast. 

" Even after making due allowance for the efi*ects of the imagination, it is 
certain that odors act as an excitant on the brain, which may be dangerous 
When long continued. They are especially dreaded by the Roman women. It is 
well known that in ancient times the women of Rome indulged in a most im- 



18^ 



THE SPECIAL SENSES. 



The Uses of the sense of smell are to guide us in th6 
choice of our food, and to warn us against bad air and un- 
healthy localities. 



IV. HEARING. 




The Ear. 



Description. — The ear is diyided into the external^ 
middle^ and internal ear. 



moderate use of baths and perfames ; but those of our times have nothing in 
common with them in this respect ; and the words of a lady are quoted, who 
said on admiring an artificial rose, ' It is all the more beautiful that it has no 
smell,'' 

" We are warned by the proverb not to discuss colors or tastes, and we may 
add odors also. Men and nations differ singularly in this respect. The Lap 
lander and the Esquimaux find the smell of fish-oil delicious. Wrangel says his 
compatriots, the Russians, are very fond of the odor of pickled cabbage, which 
forms an important part of their food ; and asafoetida, it is said, is used as a 
condiment in Persia, and, in spite of its name, there are persons who do no^ 
find its odor disagreeable any more than that of valerian."— Tfo/ic^er* of t?it 
Human Body. 



HEARING, 185 

1. The SJxternal ^ar is a sheet of cartilage curi- 
ously folded for catching sound. The auditory canal, B^ 
or tube of this ear-trumpet, is about an inch long. Acrosa 
the lower end is stretched the membrane of the tympanum 
or drum, which is kept soft by a fluid wax. 

2. The Middle ^ar is a cavity, at the bottom of 
which is the Eustachian tube, 6r, leading to the mouth. 
Across this chamber hangs a chain of three singular little 
bones, (7, named from their shape the hammer, the anvily 
and the stirrup. All together these tiny bones weigh only 
a few grains, yet they are covered by a periosteum, are sup- 
plied with blood-vessels, and articulate with perfect joints 
(one a ball-and-socket, the other a hinge), having synovial 
membranes, cartilages, ligaments, and muscles. 

3. The Internal ^ar^ or labyrinth, as it is some- 
times called from its complex character, is hollowed out 
of the sohd bone. In front is the vestibule or ante-cham- 
ber, A, about as large as a grain of wheat ; from it open 
three semi-circular canals, D, and the winding stair of the 
cochlea, or snail shell, E. Here expand the delicate fibrils 
of the auditory nerve. Floating in the liquid which fills 
the labyrinth is a httle bag containing hair-like bristles, 
fine sand, and two ear-stones {otoliths). All these knock- 
ing against the ends of the nerves, serve to increase any 
impulse given to the liquid in which they lie. Finally, to 
complete this delicate apparatus, in the cochlea are minute 
tendrils, named the fibres of Corti, from their discoverer. 
These are regularly arranged — the longest at the bottom, 
and the shortest at the top. If this spiral plate, which 
coils two and a half times around, could be unrolled and 
made to stand upright, it would form a beautiful microscopic 
harp of three thousand strings. If it were possible to strike 



186 THE SPECIAL SENSE So 

these cords as one can the keyboard of a piano, ue conld 
produce in the mind of the person experimented upon 
every variety of tone which the ear can distinguish. 

How We Hear. — Whenever one body strikes another 
in the air, waves are produced, just as when we throw a 
stone into the water a series of concentric circles surrounds 
the spot where it sinks. These waves of air strike upon 
the membrane. This vibrates, and sends the motion 
along the chain of bones in the middle ear to the fluids 
of the labyrinth. Here bristles, sand, and stones pound 
away, and the wondrous harp of the cochlea, catching up 
the pulsations,* carries them to the fibres of the auditory 
nerve, which conveys them to the brain, and gives the 
mind the idea of sound. {Physics, p. 176.) 

Care of the Ear. — The delicacy of the ear is such 
that it needs the greatest care. Cold water should not be 
allowed to enter the auditory canal. If the wax accumu- 
late, never remove it with a hard instrument, lest the 
delicate membrane be injured, but with a little warm 
water, after which turn the head to let the water run out, 
and vfipe the ear dry. The hair around the ears should 
never be left wet, as it may chill this sensitive organ. 
£f an insect get into the external ear, pour in a little oil 
to kill it, and then remove with tepid water. The object 
of the Eustachian tube is to admit air into the ear, and 
thus equalize the pressure on the membrane. If it be- 
come closed by a cold, or if, from any cause, the pressure 
be made unequal, so as to produce an unpleasant feeling 
in the ear, relief may often be obtained by grasping the ^ 
nose and forcibly swallowing. 

* The original motion is constantly modified by the medium through which it 
passes. The hristles, otoliths, and Cortian fibres of the ear and the rods and 
cones of the eye (p. 189) seem to convert the vibrations into pulsations which act 
as stimuli of the appropriate nerve. The molecular change thus produced in tho 
nerve-fibres is propa^atea to th© oram. 



BIOHT 



187 



V. SIGHT. 




The Eye, 

Description. — The eye is lodged in a bony cavity, pro- 
tected by the overhanging brow. It is a globe, about an 
inch in diameter. The ball is covered by three coats — 
(1) the sclerotic^ d, a tough, hard casing, which gives form 
to the eye, the convex, transparent part in front forming 
a window, the cornea, c\ (2) the clioroid, e, a black lining, 
to absorb the superfluous light;* and (3) the retina, b, 
the expansion of the optic nerve, 0, The eye is divided 
into the anterior and posterior chambers. In the front 
part of the latter, is the crystalline lens, a, which serves 
to bring the rays of light to a focus on the retina. The 

* Neither white rabbits nor albinos lu9ive this black lining, and hence their 
eight is confused. 



188 TUE SPECIAL SENSES. 

lens is kept in place by the ciliary processes, g, which are 
arranged hke the rays in the disk of a passion-flower. 
The anterior chamber is filled with the aqueous humor — a 
limpid liquid, and the posterior with the yitreous humor. 
The pupil, h, is a hole in the colored, muscular curtain, *, 
the iris (rainbow). 

Eyelids and Tears. — The eyelids are close-fitting 
shutters to protect the eye. The inner side is lined with 
a mucous membrane, which is exceedingly sensitive, and 
thus aids in protecting the eye from any irritating sub* 



The Eyelashes and the Tear-glands, 

stance. The looseness of the skin fayors swelling from in- 
flammation or the effusion of blood, as in a " black eye.^' 
The eyelashes serve as a kind of sieve to exclude the dustj 
and, with the lids, to shield against a blinding light. 
Just within the lashes are oil glands, which lubricate the 
edges of the lids, and prevent them from adhering to each 
other. The tear or lachrymal gland, 0, is an oblong body 
lodged in the bony wall of the orbit. It empties by sev- 



aTRUC TUB E OF TEE RETINA, 



189 



Fig. 62 



eral ducts upon the inner surface, at the outer edge of the 
upper eyehd. Thence the tears, washing the eye, run into 
the lachrymal lahe, I), a little basin with a rounded border 
fitted for their reception. On each side of this lake two 
canals, C, C\ drain off the overplus through the duct, B, 
into the nose. In old age and in disease, these canals fail 
to conduct the tears away, and hence the lachrymal lake 
ovei'flows upon the face. 

Structure of the Retina.— In 
Fig. 62 is shown a section of the reti- 
na, greatly magnified, since this mem- 
brane never exceeds g^o of an inch in 
thickness. On the inner surface next 
the vitreous humor is a lining mem- 
brane not shown in the cut; next the 
choroid, and comprising about ^ the 
entire thickness of the retina, is a 
va-st multitude of transparent, color- 
less, microscopic rods, a, evenly ar- 
ranged and packed side by side, like 
the seeds on the disk of a sunflower. 
Among them, at regular intervals, are 
interspersed the cones, 5. Delicate 
nerve fibres pass from the ends of the 
rods and cones, each expanding into 
a granular body, c, thence weaving a 
mesh, d, and again expanding into 
the granules, /. Last is a layer of fine 
nerve fibres, g, and gray, ganglionic 
cells, h, like the gray matter of the brain, whence fila- 
ments extend into i, the fibres of the optic nerve. 

The layer of rods and cones is to the eye what the 




structure of the Retina. 



190 THE SPECIAL SENSES 

bristles, otoliths^ and Oortian fibres are to the ear. In- 
deed, the nerre itself is insensible to light. At the point 
where it enters the eye, there are no rods and cones, and 




this is called the Uind spot. A simple experiment will 
illustrate the fact. Hold this book directly before the 
face, and, closing the left eye, look steadily with the right 
at the left-hand circle in Fig. 63. Move the book back 
and forth, and a point will be found where the right-hand 
circle vanishes from sight. At that moment its light falls 
upon the spot where the rods and cones are lacking. 

How We See. — There is behoved to be a kind of 
universal atmosphere, termed ether y filling all space. This 
substance is infinitely more subtle than the air, and occu- 
pies its pores, as well as those of all other substances. As 
sound is caused by waves in the atmosphere, so hght is 
produced by waves in the ether. A lamp-light, for exam- 
ple, sets in motion waves of ether, which pass in through 
the pupil of the eye to the retina, where the rods and 
cones transmit the vibration through the optic nerve to the 
brain, and then the mind sees the light. (Note, p. 186.) 

The Use of the Crystalline Lens.'^ — A convex lens, 
as a common burning-glass, bends the rays of light which 

♦ The uses of the eye are largely dependent upon the principles of Optics and 
Acoustics. They are therefore best t^e|^ted in philosophy. 



NEAR AND FAR SIGHT, 19l 

pass through it, so that they meet at a point called the 
focus. The crystalline lens converges the rays of light 

Fig. 6k. 




Diagram sfuming fuyw an image of an object is formed upon the retina by the 
Crystalline Lens. 



which enter the eye, and brings them to a focus on the 
retina.* The healthy lens has a power of changing its 
convexity so as to adapt f itself to near and to distant 
objects. (See Fig. 65.) 

Near and Far Sight. — K the lens be too convex, it 
ndll bring the rays to a focus before they reach the ret- 
i)ia ; if too flat, they will reach the retina before coming 
to a focus. In either case, the sight will be indistinct. A 



* The cornea and the humors of the eye act in the same manner as the crystal. 
Irae lens, but not so powerfully. 

♦ The simplest way of experimenting on the "adjustment of the eye" is to 
stick two stout needles upright into a straight piece of wood, — not exactly, but 
nearly in the same straight line, so that, on applying the eye to one end of the 
piece of wood, one needle {A) shall be seen about six inches oflf, and the other 
(/?) just on one side of it, at twelve inches distance. 

If the observer looks at the needle B he will find that he sees it very distinctly, 
and without the least sense of efi'ort; but the image of A is blurred and more 
or less double. Now, let him try to make this blurred image of the needle A 
distinct. He will find he can do so readily enough, but that the act is accom- 
panied by a sense of fatigue. And in proportion as A becomes distinct, B will 
become blurred. Nor will any efi'ort enable him to see A and B distinctly at the 
S^une time.— HUXI4BT. 



THE SPECIAL SENSES. 

Mg. 66. 




A^ustment of the Crystalline Lens. A, for far objects, and B.for near. 

more common defect, however, is in the shape of the globe, 
of the eye, which is either flattened or elongated. In the 
former case (see G, Fig. m), objects at a distance can be 
seen most distinctly — hence that is called far-sightedness.* 
In the latter, objects near by are clearer, and hence this 
i^ termed near-sightedness. Far-sightedness is remedied 

Fig. 66. 



Diagram 




f the position of the Retina. — B, in natural sight ; G, in 
far sight ; and C, in near sight. 



by convex glasses ; near-sightedness, by concave. When 
glasses will improve the sight, they should be worn ; f any 

* This should not be confounded with the long sight of old people, which i& 
eaused by the stiffness of the ciliary muscles, whereby tho lens cannot adapt itself 
to the varying distances of objects. 

t Dr. Henry W. Williams, the celebrated ophthalmologist, says that, in some 
cases, glasses are more necessary at six or eight years of age than to the major- 
ity of healthy eyes at sixty. Sometimes children find accidentally that they 
can see better through grandmother's spectacles. They should then be supplied 
mth their own. 



CARE OF THE EYES. IdS 

delay will be liable to injure the eyes, by straining their 
akeady impaired power. Cataract is a disease in which 
there is an opacity of the crystalHne lens or its capsules, 
which obscures the vision. The lens may be caused to be 
absorbed, or may be removed by a skillful surgeon, and the 
defect remedied by wearing convex glasses. 

Care of the Eyes.— The shape of the eye cannot be 
changed by rubbing and pressing it, as many suppose, but 
the sight may thus be fatally injured. Children troubled 
by near-sightedness should not lean forward at their work, 
.as thus the vessels of the eye become overcharged with 
blood. They should avoid fine print, and try, in every pos- 
sible way, to spare their eyes. If middle age be reached 
without especial difficulty of sight, the person is compara- 
tively safe. Most cases of squinting are caused by long- 
sightedness, the muscles being strained in the effort to 
obtain distinct vision. In childhood, it may be cured 
by a competent surgeon, who will generally cut the muscle 
which draws the eye out of place. Healthy eyes even 
should never be used to read fine print or by a dim 
tight. Serious injury may be caused by an imprudence 
of this kind. 

Reading upon the cars is also a fruitful source of harm. 
The lens, striving to adapt itself to the incessantly vary- 
ing distance of the page, soon becomes wearied. Objects 
which get into the eye should be removed before they 
cause inflammation ; rubbing in the mean time only irri- 
tates and increases the sensitiveness. If the eye be shut 
for a few moments, so as to let the tears accumulate, and 
the upper hd be then lifted by taking hold of it at the 
centre, the cinder or dust is often washed away at once. 
Trifling objects can be removed by simply drawing the 



194 THB SPECIAL SENSES, 

upper lid as far as possible over the lower one ; when the 
hd flies back to its place, the friction will detach any hght 
substance. If it becomes necessary, turn the upper lid 
©yer a pencil, and the intruder may then be wiped off 
with a handkerchief " Eye-stones ^' are a popular delu- 
sion. When they seem to take out a cinder, it is only 
because they raise the eyelid, and allow the tears to wash 
it out. N"o one should ever use an eye-wash, except by 
medical advice. The eye is too delicate an organ to be 
trifled with, and when any disease is suspected, a rehable 
physician should be consulted. This is especially neces- 
sary, since, when one eye is injured, the other, by sympa- 
thy, is hable to become inflamed, and perhaps be destroyed. 
When reading or working, the light should be at one side, 
and never in front. The position of school-room desks i%, 
therefore, of great importance. 



PRACTICAL QUESTIONS. 

1. Why does a laundress test the temperature of her flat-iron bj* 
holding it near her cheek ? 

2. VV hen we are cold, why do we spread the palms of our hands 
before the fire ? 

3. What is meant by a '* furred tongue % " 

4. Why has sand or sulphur no taste ? 

5. What was the origin of the word palatable ? 

6. Why does a cold in the head injure the flavor of our coffee ? 

7. Name some so-called flavors which are really sensations of 
louch. 

8. What is the object of the hairs in the nostrils ? 

9. What use does the nose subserve in the process of respiration ^ 

10. Why do we sometimes hold the nose when we take unplea& 
ant medicine ? 

11. Why was the nose placed over the moutii ? 



PRACTICAL QUESTIONS. 196 

12. Describe how the hand is adapted to be the instrument of 
touch- 

13. Besides being the organ of taste, what use does the tongue 
subserve ? 

14. Why is not the act of tasting complete until we swallow ? 

15. Why do all things have the same flavor when one's tongue m 
** furred " by fever ? 

16. WMch sense is the more useful — hearing or sight ? 

17. Which coat is the white of the eye ? 

18. What makes the difference in the color of eyes ? 

19. Wby do we snuff the air when we wish to obtain a distinct 
smell ? 

20. Why do red-hot iron and frozen mercury ( — 40°) produce the 
same sensation ? 

21. Why can an elderly person drink tea which to a child would 
be unbearably hot ? 

22. Why does an old man hold his paper so far from his eyes ? 

23. Would you rather be punished on the tips of your fingers 
than on the palm of your hand ? 

24. What is the object of the eyelashes ? Are the hairs straight? 

25. What is the use of winking ? 

26. When you wink, do the eyelids touch at once along theii 
whole length ? Why ? 

27. How many rows of hairs are there in the eyelashes ? 

28. Do all nations have eyes of the same shape ? 

29. Why does snuff-taking cause a flow of tears ? 

30. Why does a fall cause one to " see stars ? " 

31. Why can we not see with the nose, or smell with the eyes ? 

32. What causes the roughness of a cat's tongue ? 
83. Is the cuticle essential to touch ? 

34. Can one tickle himself ? 

35. Why does a bitter taste often produce vomiting ? 

36. Is there any danger in looking " cross-eyed" for fun ? 

37. Should school-room desks face a window ? 

38. Why do we look at a person to whom we are listening 
attentively ? 

39. Do we really feel with our fingers ? 

40. Is the eye a perfect sphere ? (See Fig. 60.) 

41. How often do we wink ? 

42. Wliy is the interior of a telescope or microscope often 
painted black ? 

43. What is " the apple of the eye ? " 

44 What form of glasses do old people require ? 



196 THE SPECIAL SENSES. 

45. Should we ever wash our ears with cold water ? 

46. What is the object of the winding passages in the nose? 

47. Can a smoker tell in the dark, whether or not his cigar if 
Hghted ? 

48. Will a nerve re-unite after it has been cut ? 

49. Will the sight give us an idea of solidity ? * 

50. Why can a skillful surgeon determine the condition of thf 
brain and other internal organs by examining the interior of the 
eye?! 

51. Is there any truth in the idea that the image of the murderer 
can be seen in the eye of the dead victim ? 

* " A case occurred a few years ago, in London, where a friend of my own per' 
formed an operation upon a young woman who had been "born blind, and, though] 
an attempt had been made in early years to cure her, it had failed. She was ablt 
just to distinguish large objects, the general shadow, as it were, without any 
distinct perception of form, and to distinguish light from darkness. She could 
work well with her needle by the touch, and could use her scissors and bodkin 
and other implements by the training of her hand, so to speak, alone. Well, mj 
friend happened to see her, and he examined her eyes, and told her that he 
thought he could get her sight restored ; at any rate, it was worth a trial The 
operation succeeded ; and, being a man of intelligence and quite aware of the 
interest of such a case, he carefully studied and observed it ; and he completely 
confirmed all that had been previously laid down by the experience of similai 
cases. There was one little incident which will give you an idea of the educa- 
tion which is required for what you would suppose is a thing perfectly simple an^ 
obvious. She could not distinguish by sight the things that she was perfects 
familiar with by the touch, at least when they were first presented to her eyes 
She could not recognize even a pair of scissors. Now, you would have supposed 
that a pair of scissors, of all things in the world, having been continually used b\ 
her, and their form having become perfectly familiar to her hands, would have beer, 
most readily recognized by her sight ; and yet she did not know what they were ; 
she had not an idea until she was told, and then she laughed, as she said, at hei 
own stupidity. No stupidity at all • she had never learned it, and it was one of 
those things which she could not know without learning. One of the earliest 
cases of this kind was related by the celebrated Cheselden. a surgeon of the early 
part of last century. Cheselden relates how a youth just in this condition had 
been accustomed to play with a cat and a dog ; but lor some time after he at- 
tained his sight he never could tell which was which, and used to be continually 
making mistakes. One day, being rather ashamed of himself for having called 
the cat the dog. he took up the cat in his arms and looked at her very attentively 
for some time, stroking her all the while ; and m this way he associated the im- 
pression derived from the touch, and made himself master (so to speak) of the 
whole idea of the animal. He then put the cat down, saying, 'Now, puss, I shall 
know you another time.' "— Cakpenter. 

t This is done by means of an instrument called the ophthalmoscope. Light is 
throT^Ti into the eye with a concave mirror, aod the interior of the organ exam- 
ined with a lens. 



Co 



N C LU S I O N 



VALUE of Health. — The body is the mstramt^nt 
which the mind uses. K it be dulled or nicked, 
the effect of the best labor will be impaired. The grandest 
gifts of mind or fortune are comparatively valueless unless 
there be a healthy body to use and enjoy them. The 
beggar, sturdy and brave with his out-door life, is really 
happier than the rich man in his palace with the gout to 
twinge him amid his pleasures. The day has gone by when 
delicacy was considered an element of beauty. Weakness 
is timid and irresolute ; strength is full of force and energy. 
Weakness walks or creeps ; strength speeds the race, wins 
the goal, and rejoices in the victory. 

False Ideas of Disease. — It was formerly supposed 
that diseases were caused by evil spirits, who entered the 
body and deranged its action. Incantations, spells, etc., 
were resorted to in order to drive them out. By others, 
disease was thought to come arbitrarily, or ae a special 
visitation of an over-ruling power. Hence, it was to be 
removed by fasting and prayer. Modem science teaches 
us that disease is not a thing, but a state. When our food 
is properly assimilated, the waste matter promptly excreted. 



198 CONCLUSION. 

and all the organs work in harmony, we are well ; when 
any derangement of these functions occurs, we are sick. 
Sickness is discord, as health is concord. K we abuse or 
misuse any instrument, we impair its ability to produce a 
perfect harmony. A ;uffering body is simply the penalty 
of violated law. 

Prevention of Disease. — Doubtless a large pro- 
portion of the ills which now afl&ict and rob us of so 
much time and pleasure might easily be avoided. A 
proper knowledge and observance of hygienic laws would 
greatly lessen the number of such diseases as consump* 
tion, catarrh, gout, rheumatism, dyspepsia, scrofula, etc. 
There are parts of England where one-half the children 
die before they are five years old. Every physiologist 
knows that at least nine-tenths of these lives could be 
saved by an observance of the simple laws of health. 
Professor Bennet, in a lecture at Edinburgh, estimated 
that 100,000 persons die annually in that country from 
causes easily preventable. 

With the advance of science, the causes of many dis- 
eases have been determined. Vaccination has been found 
to prevent or mitigate the ravages of small-pox. Scurvy, 
formerly so fatal among sailors that it was deemed ^^a 
mysterious infliction of Divine Justice against which man 
strives in vain,^' is now entirely avoided by the use of vege- 
tables or lime-juice. Cholera, whose approach still strikes 
dread, and for which there is no known specific, is but the 
penalty for filthy streets, bad drainage, and over-crowded 
tenements, and may be controlled, if not prevented, by 
suitable sanitary measures. It was, no doubt, the inten- 
tion that we should wear out by the general decay of all 
the organs, rather than by the giving out of any single 



PREVENTION OF DISEASE. 19^ 

part, and that all should work together harmoniously un- 
til the vital force is exhausted. 

Cure of Disease. — The first step in the cure of any 
disease is to obey the law of health which has been vio- 
lated. If medicine be taken, it is not to destroy the dis- 
ease, since that is not a thing to be destroyed, but to hold 
the deranged action in check while nature repairs the 
mjury, and again brings the system into harmonious 
movement. This tendency of nature is our chief reliance. 
The best physicians are coming to have diminished con- 
fidence in medicine itself, and to place greater dependence 
upon sanitary tind hygienic measures, and the efforts which 
nature always makes to repair injuries and soothe dis- 
ordered action. They endeavor only to give her a fail 
chance, and sometimes to assist her by the intelligent 
employment of proper medicines. The indiscriminate use 
of patent nostrums and sovereign remedies of whose con- 
stituents we know nothing, and by which powerful drugs 
are imbibed at hap-hazard, cannot be too greatly depre- 
cated.* When one needs medicine, he needs also a com- 
petent physician to advise its use. 

Death and Decay. — By a mystery we cannot under- 
stand, life is linked with death, and out of the decay of 
our bodies they, day by day, spring afresh. At last the 
vital force which has held death and decay in bondage, 
ind compelled them to minister to our growth, and serve 



* A traveler in AMca states tiiat he was snrprised and delighted to find in 
the posseesion of the chief medicine man of one of the interior tribes a care- 
folly preserved copy of the New York Tribune. On inquiry, he found that it 
was exceedingly valuable, as a minute fragment of it either rubbed on the out- 
3ide or taken inwardly was a sovereign remedy for as long a list of diseases as 
^ver graced the advertisement of an American pain-kiiler. The mania which 
some people possess for tippling with patent medicines is no more sensible than 
iie trust of the poor savaeje in a New York daily. 



200 aONCLU8IONo 

the needs of our life^ faints and yields the struggle, 
^hese powers which have so long time been our servants, 
gather about our dying couch, and their last offices usher 
us into the new life and the grander possibiHties of the 
world to comCo This last birth, we who see the fading, 
not the dawning life, call death.. 

** O Father \ grant Thy love divine. 
To make these mystic temples Thine. 
When wasting age and wearying strife 
Have sapp'd the leaning walls of life; 
When darkness gathers over all. 
And the last tottering pillars fall. 
Take the poor dust Thy mercy warms^ 
And mould it into heavenly forms." 



Appendix 



H 



I N T S 

ABOUT 

The Sick-room. 



A SICK-ROOM should be the lightest and cheeriest in the 
house, A small, close, dark bedroom or a recess is bad 
enough for one in health, but unendurable for a sick person. In a 
case of fever, and in many acute diseases, it should be remote from 
the noise of the family ; but when one is recovering from an acci- 
dent, and in all attacks where quiet is not needed, the patient may 
be where he can amuse himself by watching the movements of the 
household, or looking out upon the street. 

The ventilation must be thorough. Bad air will poison the sick 
and the well alike. A fireplace is, therefore, desirable. Windows 
should open easily. By carefully protecting the patient with extra 
blankets, the room may be frequently aired. If there be no direC 
draught, much may be done to change the air, by simply swingin; 
an outer door to and fro many times. 

A bare floor, with strips of carpet here and there to deaden noisCi 
is cleanest, and keeps the air freest from dust. Cane-bottomed 
chairs are preferable to upholstered ones. All unnecessary furni- 
ture should be removed out of the way. A straw bed or a mattress 
is better than feathers. The bed-hangings, lace curtains, etc., should 
be taken down. Creaking hinges should be oiled. Sperm candles 
are better than kerosene lamps. 

Never whisper in a sick-room. All necessary conversation should 
be carried on in the usual tone of voice. Do not call a physician 



20J4, WHAT TO DO 

unnecessarily, but if one be employed obey his directions implicitly. 
Never give nosrrums over-officious friends may suggest. Do not 
allow visitors to see the patient, except it be necessary. Never 
bustle about the room, nor go on tip-toe, but move in a quiet, ordi- 
nary way. Do not keep the bottles in the continued sight of the sick 
person. Never let drinking-v/ater stand in the room, as it will ab- 
sorb noxious gases. Do not raise the patient's head to drink, but 
have a cup with a spout, or use a bent tube, or even a straw. Do 
not tempt the appetite when it craves no food. Bathe frequently, but 
let the physician prescribe the method. Give written directions to 
the watchers. Have all medicines carefully marked. Remove all 
soiled clothing, etc., at once from the room. Change the linen much 
oftener than in health. When you wish to change the sheets, and 
the patient is unable to rise, roll the under sheet tightly lengthwise 
to the middle of the bed ; put on the clean sheet, with half its width 
folded up, closely to the other roll ; lift the patient on to the newly- 
made part, remove the soiled sheet, and then spread out the clean one. 



DISINFECTANTS. 

An excellent disinfectant may be made by dissolving in a pail of 
water either of the following : (i), a quarter of a pound of sulphate 
of zinc and two ounces of common salt, for each gallon of water ; 
(2), a pound and a half of copperas for each gallon of water. Towels, 
bed-linen, handkerchiefs, etc., should be soaked at least an hour, in 
a solution of the first kind, and then be boiled, before washing. 
Vaults, drains, vessels used in the sick-room, etc., should be dis- 
infected by a solution of the second kind ; chloride of lime may also 
be used for the same purpose. Rooms, furniture, and articles that 
cannot be treated with the solution of the first kind, should be 
thoroughly fumigated with burning sulphur. 



WHAT TO DO TILL THE DOCTOR 
COMES. 

Burns. — When a person's clothes catch fire, quickly lay him on 
the ground, wrap him in a coat, mat, shawl, carpet, or in his own 
clothes, as best you can to extinguish the fire. Pour on plenty of 
water till the half-burned clothing is cooled. Then carry the suf. 



TILL THE DOCTOR COMES, 20b 

ferer to a warm room, lay him on a table or a carpeted floor, and 
with a sharp knife or scissors remove his clothing. 

The treatment of a burn consists in protecting from the air."^ Dress 
the wound with carbolic acid salve or cotton-batting, or dredge with 
flour. Wrap a dry bandage upon the outside. Then remove the 
patient to a bed and warmly cover. f An excellent remedy is to apply 
soft cloths kept wet with sweet oil, or cold water which contains all 
the " cooking soda " that it zuill dissolve. Apply cold water to a smaL 
burn till the smart ceases, and then cover with ointment. Do not 
remove the dressings until they become stiff and irritating ; then take 
them from a part at a time ; dress and cover again quickly. 

Cuts, Wounds, etc.— The m.ethod of stopping the bleeding has 
been described on page 126. If an artery is severed, a physician 
should be called at once. If the bleeding is not profuse, apply cold 
water unHl it ceases, dry the skin, draw the edges ot the wound to- 
gether, and secure them by strips of adhesive plaster. Protect with 
an outer bandage. This dressing should remain for several days. 
In the meantime wet it frequently with cold water to subdue in 
flammation. When suppuration begins, wash occasionally with 
tepid water and Castile soap. 

Bleeding from the Nose is rarely dangerous, and often 
beneficial. When it becomes necessary to stop it, sit upright and 
compress the nostrils between the thumb and forefinger, or with the 
thumb press upward upon the upper lip. A piece of ice, a snow= 
ball, or a compress wet with cold water may be applied to the back 
of the neck. 

A Sprain is often more painful and dangerous than a disloca- 
tion. Wrap the injured part in flannels wrung out of hot water, and 
cover with a dry bandage, or, better, with oiled silk. Liniments and 
stimulating applications are injurious in the first stages, but useful 
when the inflammation is subdued. Do not let the limb hang down. 



♦ It is a ^eat mistake tc suppose that salves will ** draw out the fire " of a burn 
or heal a bruise or cut. The vital force must unite the divided tissue by the de 
posit of material, and the formation of new cells. 

t If a burn be near a joint or on the face, even if small, let a doctor see it, and 
do not be in any hurry about having X healed. Remember that with all the care 
and skill which can be used, contractions will sometimes take place. The danger 
*o life from a burn or scald is not in proportion to its severity, but to its extent- 
that is, a small part, such as a hand or a foot or a face, may be burned so deeply 
as to cripple it for life, and yet not much endanger the general health ; but a 
slight amount of burning, a mere scorching, over two-thirds of the body, maj 
prove fatal.— Hope - 



206 WJBLA.T TO DO 

It must be kept quiet, even after all pam has ceasedc If used te 
quickly, dangerous consequences may ensue. 

Diarrhea^ Cholera Infantum, etc., are often caused by mat- 
ing indigestible food or checking of the perspiration ; but more fre* 
quently by peculiar conditions of the atmosphere, especially in large 
cities. If the limbs are cold, give a hot bath, and rub thorougMj. 
If possible^ go to bed and lie quietly on the back. Rest is better them 
medicine. If there be pain, apply repeatedly to the abdomen fian* 
nels wrung out of hot water. If medicine is needed, take fifteen 
drops of peppermint and thirty of paregoric !n a wine-glass of warm 
water ; or an adult may take twenty drops of spirits of camphor and 
thirty to forty drops of laudanum. Laudanum should never be given 
to an infant, except by a physician's order. Eat no fruit, vegetables, 
pastry, or pork. If much thirst exist, give small pieces of ice, or 
cold tea or toast-water. 

Croup. — Send at once for a doctor. Induce vomiting by S3n-up 
of ipecac or mustard and water. Put the feet in a hot bath. Apply 
hot fomentations rapidly renewed to the chest and throat. 

Sore Throat. — Wrap the neck in a wet bandage, and cover with 
red flannel or a woolen stocking. Gargle the throat frequently with 
a solution of a tea-spoonful of salt in a pint of water, or thirty grains 
of chlorate of potash in a wine-glass of water. 

Fits, Apoplexy, Epilepsy, etC-^Loosen the clothing and 
raise the head and shoulders, but do not bend the head forward on 
the neck. Apply cold to the head, and heat to the feet. Follow 
with an emetic. In a child, a full hot bath is excellent. When 
there are convulsions, prevent the patient from injuring himself; 
especially put something in his mouth to keep him from biting his 
tongue. 

Toothache and Earache.— Insert in the hollow tooth, or in 
the ear, cotton wet with laudanum, spirits of camphor, or chloroform. 
When the nerve is exposed, wet it with creosote or carbolic acid 
Hot cloths or a hot brick wrapped in cloth and held to the face 
will often relieve the toothache. In a similar manner treat the ear 
wetting the cloth in hot water, and letting the vapor pass into the 
ear. 

Choking. — Ordinarily a smart blow between the shoulders, 
causing a compression of the chest and a sudden expulsion of the 
air from the lungs, will throw out the substance. If the person caD 
swallow, and the object be small, give plenty of bread or potato, and 
water to wash it down. Press upon the tongue with a spoon, when, 
perhaps, you may see the oflfending body, and draw it out with 



TILL THE DOCTOR COMES. 201 

a blunt pair of scissors. If neither of these remedies avail, give an 
emetic of syrup of ipecac or mustard and warm water. 

Frost Bites are frequently so sudden that one is not aware 
when they occur. In Canada it is not uncommon for persons meet- 
ing in the street to say, '* Mind, sir, your nose looks whitish." The 
blood cools and runs slowly, and the blood-vessels become choked 
and swollen. Keep from the heat. Rub the part quickly with snow 
if necessary for hours, till the natural color is restored. If one is 
benumbed with cold, take him into a cold room, remove the wet 
clothes, rub the body dr}% cover with blankets, and give a little 
warm tea or weak brandy and water. On recovering, let him be 
brought to a fire gradually.* 

Fevers, and many acute diseases, are often preceded by a loss 
of appetite, headache, shivering, "pains in the bones," indisposition 
to work, etc. In such cases, sponge with tepid water, and rub the 
body till all aglow. Go to bed, place hot bricks to the feet, take noth- 
ing but a little gruel or beef tea, and drink moderately of warm, 
cream-of-tartar water. If you do not feel better the next morning, 
call a physician. If that be impossible, take a dose of castor-oil or 
Epsom salt. 

Sun-stroke is a sudden prostration caused by intense heat. The 
same effect is produced by the burning rays of the sun and the fierce 
fire of a furnace. When a person falls under such circumstances, 
place your hand on his chest. If the skin be cool and moist, it is 
not a sun-stroke ; but if it be dry and " biting hot," there can be no 
mistake. Time is now precious. At once carry the sufferer to the 
nearest pump or hydrant, and dash cold water on the head and chest 
until consciousness is restored. — Dr. H. C. Wood. 

To prevent sun-stroke, wear a porous hat, and in the top of it place 
a wet handkerchief; also drink freely of water, not ice cold, to in- 
duce abundant perspiration. 

Asphyxia, or apparent death, whether produced by drowning, 
suffocation, bad air, or coal gas, requires very similar treatment. 
Send at once for blankets, dry clothing, and a physician. Treat the 
sufferer upon the spot, if the wealher be not too unfavorable. 

I. Loosen the clothing about the neck and chest. 



♦ If you are caught in a snow-storm, look for a snow-bank in the lee ot a hiE, 
or a wood out of the wind, or a hollow in the plain filled with snow. Scrape out 
a hole big enough to creep into, and the drifting snow will keep you warm. Men 
and animals have been preserved after days of such imprisonment. Remembel 
that if you give way to sleep in the open field, you will never awake. 



^08 TILL THE DOCTOR COMES. 

2. Turn the patient on his face, open the mouth, draw out thfi 
tongue, and cleanse the nostrils, so as to clear the air-passages. 

3. Place the patient on his back, grasp his arms firmly above 
the elbows, and pull them gently upward until they meet over the 
head, in order to draw air into the lungs. Then bring the armf^ 
back by the side, to expel the air. Repeat the process about fifteer^ 
times per minute. Alternate pressure upon the chest, and blowing 
air into t^ jiouth through a quill or with a pair of bellows, may aid 
your efforts. Excite the nostrils with snuff or smelling salts, or bj 
passing hartshorn under the nose. Do not cease effort while therf • 
is hope. Life has been restored after five hours of suspended ani 
mation. 

4. When respiration is established, wrap the patient in dry, warm 
clothes, and rub the limbs under the blankets or over the dry cloth- 
ing energetically toward the heart. Apply heated flannels, bottles of 
hot water, etc., to the limbs, and mustard plasters* to the chest. 

Foreign Bodies in the Ear. — Insects may be killed by drop- 
ping a little sweet oil into the ear. Beans, peas, matches, etc , may 
generally be removed by cautiously syringing the ear out with tepid 
water. Do not use much force lest the tympanum be injured. If 
this fail, dry the ear, stick the end of a little linen swab into thick 
glue, let the patient lie on one side, put this into the ear until it 
touches the substance, keep it there three-quarters of an hour while 
it hardens, and then draw them all out together. Be careful that 
the glue does not touch the skin at any point, and that you are at 
work upon the right ear. Children often deceive one as to the ea) 
which is affected. 

Foreign Bodies in the Wose, such as beans, cherry-pits, 
etc., may be frequently removed by closing the opposite nostril, and 
then blowing into the child's mouth forcibly. The air, unable tc 
escape except through the other nostril, will sweep the obstructior 
before it. 

* The best mustard poultice is the paper plaster now sold by every druggist 
!Lt is always rea iy, and can be carried by a traveler. It has only to be dipped in 
mzXjsx^ and applied at once. 



ANTIDOTES TO 1' IS N S. 209. 



ANTIDOTES TO POISONS. 

Acids : Nitric (aqua fortis), hydrochloric (muriatic), sulphuric (oil 
of vitriol), oxalicy etc. — Drink a little water to weaken the acid, or, 
still better, take strong soap-suds. Stir some magnesia in water, 
and drink freely. If the magnesia be not at hand, use chalk, soda, 
lime, whiting, soap, or even knock a piece of plaster from the wall, 
and scraping off the white outside coat pound it fine, mix with milk 
or water, and drink at once. Follow with warm water, or flax-seed 
tea. 

Alkalies : Potash, soda, ley, ammonia (hartshorn). — Drink weak 
vinegar or lemon juice. Follow with castor or linseed oil, or thick 
cream. 

Antimony: Antimonial wine^ tartar emetic, etc. — Drink strong, 
green tea, and in the mean time chew the dry leaves. The direct 
antidote is a solution of nut-gall or oak-bark. 

Arsenic : Cobalt, Scheele's green, Jiy-powder, ratsbane^ etc. — Give 
plenty of milk, whites of eggs, or induce vomiting by mustard and 
tvarm water, or even soap-suds. 

Bite of a Snake or a Mad Dog.— Tie a bandage above the 
wound, if on a limb. Wash the bite thoroughly, and, if possible, let 
the person suck it strongly. Rub some lunar caustic or potash in 
the wound, or heat the point of a small poker or a steel-sharpener 
white hot, and press it into the bite for a moment. It will scarcely 
cause pain, and will be effectual in arresting the absorption of the 
poison, unless a vein has been struck. Whiskey drank freely is also 
an excellent remedy. 

Copper: Sulphate of copper {blue vitriol), acetate of copper {veidi- 
gris). — Take whites of eggs or soda. Use milk freely. 

Laudanuni : Opium^ paregoric, soothing cordial, soothing syrup ^ 
etc. — Give an emetic at once of syrup of ipecac or mustard and 
warm water, etc. After vomiting, use strong coffee freely. Ktej. 
the patient awake by pinching, pulling the hair, walking about 
dashing water in the face, and any expedient possible. 

Iiead : White uad, acetate of lead (sugar of lead), red lead, — Give 
an emetic of syrup of ipecac, or mustard and warm water, or salt and 
water. Follow with a dose of Epsom salt. 

Matclies : Phosphorus. — Give magnesia, chalk, whiting, or even 
lour in water, and follow with mucilaginous drinks. 

Mercury Calomel, chloride of mercurv <cc:c*osive sublimate, hug 



210 ANTIDOTES. 

poison), red precipitate, — Drink milk copiously. Take the whites o? 
eggs, or even stir flour in water, and use freely. 

Nitrate of Silver (lunar caustic). — Give salt and water, and 
follow with castor-oil. 

Nitrate of Potash, (saltpetre, nitre). — Give mustard and warai 
water, or syrup of ipecac. Follow with flour and water, and cream 
or sweet-oil. 

Prussic Acid (oil of bitter almonds), cyanide of potassium j^ 
Take a tea-spoonful of hartshorn in a pint of water. Apply smelling 
salts to the nose, and dash cold water in the face. 

Sting of an Insect. — Apply a little hartshorn or spirits of 
camphor, or soda moistened with water, or a paste of clean earth 
and saliva. 

Sulphate of Iron (green vitriol).— Give syrup of ipecac, or 
mustard and warm water, or any convenient emetic ; then magnesia 
and water. 



Questions 



FOR 



Class Use 



l%e questions include the notes. The figurei refer to the pagtu 



INTRODUCTION. 

Illustrate the value of physiological knowledge. Why should 
physiology be studied in youth? When are our habits formed? 
How do habits help us ? Why should children prize the lessons of 
experience? How does Nature punish a violation of her laws? 
Name some of Nature's laws. What is the penalty of their viola- 
tion ? Name some bad habits and their punishments. Some good 
habits and their rewards. How do the young ruin their health ? 
Compare one's constitution with a deposit in the bank. Can one in 
youth lay up health as he can money for middle or old age ? (See 
Conclusion) Is not the preservation of one's health a moral duty? 
What is suicide ? 



THE SKELETON. 

How many bones are there in the body? Is the number fixed? 
Is the length of the different bones proportional? What is an 
organ ? A function ? Name the three uses of the bones. Why do 
the bones have such diiferent shapes ? 

20. Why are certain bones hollow? Round? Illustrate What is 



212 QUESTIONS FOE CLASS USBo 

the composition of bone ? How does it vary? How can you remove 
the mineral matter? The animal matter? Why is a burned bone 
white and porous? What is the use of each of the constituents of a 
bone ? What food do dogs find in bones ? What is ** bone black ?" 

21. What is ossification ? Why are not the bones of children as 
easily broken as those of aged persons ? Why do they unite so 
much quicker ? What are the fontanelles ? 

22. Describe the structure of a bone. What is the object of the 
filling ? Why does the amount vary in ditterent parts of a bone ? 
What is the appearance of a bone seen through a microscope? 
What is the periosteum ? Is a bone once removed ever restored ? 

23. What are the lacunae? The Haversian canals? Why so 
called? How do bones grow? Illustrate How does a broken 
bone heal ? How rapidly is bone produced ? Illustrate. 

24. Objects of ** splints?" Describe how a joint is packed. 
Lubricated. How are the bones tied together? Name the three 
general divisions of the bones. What is a tissue ? Illustrate. 

25. What is the object of the skull? Which bone is movable? 
How is the lower jaw hinged ? 

26. Describe the construction of the skull. What is a suture ? 
Tell how the peculiar form and structure of the skull adapt it for 
its use. Illustrate the impenetrability of the skull. Describe the 
experiment of the balls. What does it show? 

27. What two cavities are in the trunk ? Name its principal bones. 
Describe the spine. What is the object of the processes? Of the 
pads? Why is a man shorter at night than in the morning? 

28. Describe the perfection of the spine. The articulation of tho 
skull with the spine. Why is the atlas so called ? 

29. Describe the ribs. What is the natural form of the chest} 
Why is the thorax or chest made in separate pieces? 

30. How do the hip-bones give solidity? What two sets of limbs 
branch from the trunk ? State their mutual resemblance. 

31. Name the bones of the shoulder. Describe the collar-bone 
The shoulder-blade. Name the bones of the arm. 

32. Describe the shoulder-joint. The elbow-joint. The wrist. 

33. Name the bones of the hand. The fingers. Describe then 
articulations. What gives the thumb its freedom of motion? In 
what lies the perfection of the hand ? 

34. Describe the hip-joint. What gives the upper limbs more 
freedom of motion than the lower? How does the pressure of the 
air aid us in walking ? Illustrate. How do the gestures of the hand 
ertforce our ideas and feelings ? 



THE MUSCLES. 21^ 

35. Name the bones of the lower limbs. Describe the knee-joint. 
The patella. What is the use of the fibula? Name the bones of 
the foot. What is the use of the arch of the foot ? What makes 
the step elastic? 

36. Describe the action of the foot as we step. What are the 
causes of deformed feet? What is the natural position of the big 
toe ? Did you ever see one lying in a straight line with the foot^ 
HS shown in statuary and paintings ? How should we have our 
iboots and shoes made ? What are the effects of high heels ? Of 
narrow heels? Of narrow toes? Of tight-laced boots? Of thin 
i^oles ? 

37. What are the rickets ? Cause of this disease ? Cure ? Causes 
^f spinal curvature ? Cure ? What is a felon ? Cure ? Cause of 
bow-legs? Cure? Is there any provision for remedying defects in 
[he body? Name one. What is the correct position in sitting at 
one's desk ? Is there any necessity for walking and sitting erect ? 
Describe the bad effects of a stooping position. 

38. What is a sprain ? Why does it need special care ? What is 
a dislocation? 



-♦4-^ =— 



THE MUSCLES» 

43. What is the use of the skeleton? How is it concealed? 
Why is it the image of death? What are the muscles ? How many 
ire there ? How are they arranged ? What property have they ? 

44. Where is the biceps? The triceps? How do the muscles 
move the limbs? Illustrate. What is the cause of squinting? 
Cure? (See page 193.) Name and define the two kinds of muscles. 
Illustrate each. What is the structure of a muscle ? Of what is a 
fibril itself composed ? 

45. How does the peculiar construction of the muscle confer 
strength? Describe the tendons. What is their use? Illustrate 
the advantages of this mode of attachment. 

46. What two special arrangements of the tendons in the hand ? 
Their use ? How is the rotary motion of the eye obtained ? What 
is a lever? Describe the three classes of levers. Illustrate each. 

47. Name the muscles of the eye. Describe their action. De- 
scribe the head as a levero What part of the body illustrates the 
three kinds of levers? 



2lJi, qUE STI N S FOR CLASS USE. 

48. Give an illustration of the second class of levers. The third 
class. Why is the tendon of Achilles so named? What is the ad- 
vantage of the third class of levers ? 

49. Why used in the hand ? What class of lever is the lower jaw? 
What advantages are gained by the enlargement of the bones at 
ihe joints? Illustrate. 

50. How do we stand erect? Is it an involuntary act? Why 
eannot a child walk at once, as many young animals do ? Why 
can we not hold up the head easily when we walk on " all fours ? " 
Why cannot an animal stand erect as man does ? Describe the pro- 
cess of walking. 

51. Show that walking is a process of falling. Describe the pro- 
cess of running. What causes the swinging of the hand in walk- 
ing? Why are we shorter when walking? Why does a person 
when lost often go in a circle ? What is the muscular sense ? 

52. Its value ? Value of exercise ? Danger of violent exercise ? 
For what purpose should we exercise ? Should exercise be in the 
open air? 

53. What is the rule for exercise ? Is a young person excusable, 
who leads a sedentary life, and yet takes no daily out-door exer- 
cise ? What will be nature's penalty for such a violation of her 
law? Will a postponement of the penalty show that we have es- 
caped it? Ought a scholar to study during the time of recess? 
Will a promenade in the vitiated air of the school-room furnish 
suitable exercise ? What is the best time for taking exercise ? Who 
can exercise before breakfast ? What are the advantages of the dif- 
ferent kinds of exercise? Should we not walk more? 

54. State some of the wonders of the muscles. What is the St. 
Vitus's Dance? Cure? 

55. What is the locked-jaw? Causes? The gout? Cause? Cure? 
The rheumatism ? Its two forms ? Peculiarity of the acute ? 

56. Danger ? Is there any particular mode of treating it ? What 
is the lumbago ? Give instances. What is a ganglion ? Its cure ? 
A. bursa? 

^^^ 

THE SKIN. 

61. What are the uses of the skin ? Describe its adaptation to its 
place. What is its function as an organ ? Describe the structure 
of the skin. The sensitiveness of the cutis. The insensitiveness 
of the cuticle. 



THE SKINo 215 

62. How is the skin constantly changing ? The shape and num- 
ber of the cells? Value of the cuticle ? 

63. What is the complexion ? Its cause? Why is a scar white? 
What is the cause of "tanning?" What are freckles? Albinos? 
Describe the action of the sun on the skin. Why are the hairs and 
the nails spoken of under the head of the skin ? 

64. Uses of the hair? Its structure? What is the hair-bulbP 
What is it called? How does a hair grow? When can it be re- 
stored, if destroyed? What is the danger of hair-dyes? Are they 
of any real value ? 

65. How can the hair stand on end ? How do horses move their 
skin? Is there any feeling in a hair? Illustrate the indestructi- 
bility of the hair. The uses of the nails. 

66. How do the nails grow? What is the mucous membrane? 
Its composition ? The connective tissue ? Why so called ? 

67. What use does it subserve? What is its character? How 
does the fat exist in the body ? Its uses ? 

68. Where is there no fat ? Why are the teeth spoken of in con- 
nection with the mucous membrane ? Name and describe the four 
kinds of teeth. What are the milk-teeth ? Describe them. 

69. What teeth appear first ? When do the permanent teeth ap- 
pear ? Describe their growth. Which one comes first ? Last ? 

70. Describe the structure of the teeth. How are the teeth fitted 
in the jaw? Why do the teeth decay? 

71. What care should be taken of the teeth? What caution 
should be observed ? What are the oil glands ? 

72. Use of this secretion ? What are the perspiratory glands ? 
State their number. Their total length ? What are the " pores " of 
the skin ? What is the perspiration ? 

73. What is the constitution of the perspiration ? Illustrate its 
value. Name the three uses of the skin. Illustrate the absorbing 
power of the skin. Why are cosmetics and hair-dyes injurious ? 

74. What relation exists between the skin and the lungs ? When 
is the best time for a bath? Why? Value of friction ? 

75. Should a bath be taken just before or after a meal ? Is soap 
beneficial? What is the ** reaction?" Explain its invigorating 
influence. How is it secured ? General effect of a cold bath ? Of 
a warm bath ? If we feel chilly and depressed after a bath, what is 
the teaching ? Describe the Russian vapor bath. 

76. Why is the sea-bath so stimulating ? How long should one 
remain in any bath ? How does clothing keep us warm ? Ex- 
olain the use of linen as an article of clothing. Cotton, Woolen, 



216 QUESTIONS FOR CLASS USE. 

Flannel. How can we best protect ourselves against the changes 
of our climate ? 

77. What colored clothing is best adapted for all seasons ? Value 
of the nap ? Furs ? Thick vs. thin clothing ? Should we wear 
thick clothing during the day, and in the evening put on thin cloth- 
ing? Can children endure exposure better than grown persons? 
What is the erysipelas ? How relieved ? 

78. The dropsy? Corns? Cause? Cure? In-growing nails? 
Cure? Warts? Cure? Chilblain? 

79. Cause? Preventive? Wens? Cure? 



RESPIRATION AND THE VOICE. 

83. Name the organs of respiration and the voice. Describe the 
larynx. The epiglottis. The oesophagus. What is meant by food 
" going the wrong way ? " 

84. Describe the vocal cords. Their use. How is sound pro- 
duced ? 

85. How are the higher tones of the voice produced ? The lower? 
Upon what does loudness depend ? A falsetto voice ? What is the 
cause of the voice *■ changing?" What is speech? Vocalization? 
Could a person talk without his tongue? Illustrate. How are 
talking-machines made ? 

86 How is a formed by the voice ? What is h ? Difference be- 
tween a sigh and a groan ? What vowel sounds are made in laugh' 
ing? Does whistling depend on the voice ? 

87. Tell how the various consonants are formed. What are the 
labials? The dentals? Thelinguals? What vowels does a child 
pronounce first? Describe the wind-pipe. The bronchi. The 
bronchial tubes. Why is the trachea so called ? 

88. Describe the structure of the lungSo What are the lungs of 
slaughtered animals called ? Why will a piece of the lungs float on 
water ? 

89. Name the wrappings of the lungs. Describe the pleura. How 
is friction prevented? What are the cilia? What is their use? 
What two acts constitute respiration ? In what two ways may the 
position of the ribs change the capacity of the chest ? 

90. Describe the process of respiration. Expirationc How often 



RESriRATION AND THE VOICE. 211 

do we breathe ? Describe the diaphragm. What is sighing ? Cough- 
ing ? Sneezing ? Snoring ? 

gi. Laughing ? Crying ? Hiccough ? Yawning ? Its value ? 
What is meant by the breathing capacity ? How does it vary? How 
much, in addition, can the lungs expel forcibly? How much of the 
breathing capacity is only available through practice ? Value of this 
extra supply? Can we expel all the air from our lungs ? 

92. Value of this constant supply? How constant is the need of 
air? What is the vital element of the air? Describe the action of 
the oxygen in our lungs. What does the blood give up? Gain? 
How can this be tested ? What are the constituents of the air ? 
What are the peculiar properties and uses of each ? 

93. What is the condition of the air we exhale ? Which is the 
most dangerous constituent? Describe the evil effects of re-breath- 
ing the air. For what is the "Black Hole of Calcutta" noted? 
Give other illustrations of the dangers of bad air. What is meant 
by the "erms of disease floating in the air. 

94. Describe the need of ventilation. Will a single breath pol- 
lute the air ? What is the influence of a fire or a light ? Of a hot 
stove ? When is the ventilation perfect ? What diseases are largely 
owing to bad air? Should the windows and doors be tightly closed 
if we have no other means of ventilation? Is not a draught of air 
dangerous? How can we prevent this, and yet secure fresh air? 
Must pure air necessarily be cold air? 

95. Are school-rooms properly ventilated ? What is the effect ? 
Are churches ? Are our bed-rooms ? Can we, at night, breathe 
anything but night air? Is the night air out-of-doors injurious? 
Ans. It is, in times and places of malaria, and should be carefully 
avoided, even at the risk of bad air in-doors. 

q6. Describe some of the wonders of respiration. How is con- 
striction of tlie lungs produced ? When may clothing be considered 
tight ? 

97. What are the dangers of tight-lacing? Which would make 
the stronger, more vigorous, and longer-lived person, the form 
shown in A or B^ Fig. 33 ? Is it safe to run any risk in this dan- 
gerous direction? Wliat is the bronchitis? Pleurisy? Pneu- 
monia? 

98. Consumption? What is one great cause of this disease.? 
How may a constitutional tendency to this disease be warded off in 
youth? Ans. Besides plenty of fresh air and exercise, care should 
be taken in the diet. Rich pastry, unripe fruit, salted meat, and 
acid drinks should be avoided, and a certain quantity of fat shoul*:^ 



218 QUESTIONS FOR CLASS C8E. 

be eaten at each meal. — Bennett. What is asphyxia? Describe 
the process for restoring such a person. (See Appt .tdix,) What is 
the diphtheria? Its peculiarity? Danger? The croup? Its 
characteristics? Remedy? (See Appendix.) 
99. Causes of stammering ? How cured ? 



--♦♦-^ 



THE CIRCULATION. 

105. Name the organs of the circulation. Does the blood per- 
meate all parts of the body? What is the average amount in each 
person ? Its composition ? The plasma ? The red corpuscles ? 
The white ? 

106. What is the size of a red cell ? Are the shape and size uni- 
form? Value of this? Illustrate. Are the disks permanent? 

107. What substances are contained in the plasma? In what 
sense is the blood " liquid flesh ?" What is the use of the red disks' 
What is the office of the oxygen in the body? Where is the blood 
purified ? 

108. What is transfusion? Give some illustrations. Is it of 
value ? What is the cause of coagulation of the blood ? Value of 
this property? 

109. Has the fibrin any other use? What organ propels the blood? 
What is the location of the heart? How large is it ? Put your hand 
over it ? _ 

no. What is the pericardium? Describe the systole? The dias- 
tole. How many chambers in the heart ? What is their average size ? 
What is meant by the right and the left heart ? What are the auri- 
cles ? Why so called ? The ventricles ? 

111. What is the use of the auricles? The ventricles? Which 
are made the stronger? 

112. Show the need of valves in the ventricles. Why are there 
.^o valves in the auricles? Draw on the b .ard the form of the 
waives. Name them. 

113. Describe the tricuspid valve. The bicuspid. How are these 
valves strengthened? What peculiarity in the attachment of these 
cords? Describe the semi-lunar valves. What are the arteries? 
Why so named ? 

114. What is their use ? Their structure? How does their das' 
ticity act ? What is meant by a " collateral circulation ? " How are 



THE CIRCULATION, 21d 

the arteries protected ? Where are they located ? Give a general 
description of the arterial system. What is the aorta ? What is the 
pulse? On which arteries can we best feel it? 

115. What is the average number of beats per minute? How and 
why does this vary? Why does a physician feel a patient's pulse? 
What are the veins ? What blood do they carry ? Describe the venous 
svstem. What vein does not lead toward the heart? Describe tl"' 
valves of the veins. What valves of the heart do they resemble ? 

116. Where and how can we see the operation of these valves * 
What are the capillaries ? What changes take place in this system / 
What are varicose veins ? 

117. Describe the circulation of the blood as seen in the web of a 
frog's foot. In what two portions is the general circulation divided ? 
Who discovered the circulation of the blood ? How was the dis- 
covery received ? What remark did Harvey make ? What does 
that show? 

1 18-9. Describe the route of the blood by the diagram, i. The 
lesser circulation ; 2. The greater circulation. What is the velocity 
of the blood ? How long does it require for all the blood to pass 
through the heart ? How has this been estimated ? What is the 
shortest route the blood can take ? The longest ? How long does 
it take the blood to make the tour of the body? How has this been 
estimated? What is the average temperature of the body? How 
much does this vary in health? Ans. Not more than 2^, even in the 
greatest extremes of temperature. — Flint. 

120. How and where is the heat of the body generated ? How is 
it distributed ? In what diseases is the variation of temperature 
marked ? How is the temperature of the body regulated ? 

I2T. In what way does life exist through death? Is not this as 
true in the moral as in the physical world ? What does it teach ? 
How rapidly do our bodies change? What are the three vital 
organs ? 

122. Name some of the wonders of the heart. 

123. What is the lymphatic circulation? What is the thoracis 
duct ? The lymph ? The glands? 

124. What is the office of the lymphatics? What are the lacteals. 
Give some illustrations of the action of the lymphatics of the differ 
ent organs. Should we use wall-paper having much green ? What 
is meant by the sub-cutaneous insertion of morphine ? How do 
hibernating animals live during the winter? 

125. What is a congestion? Its cause? Blushing? Why does 
terror cause one to grow cold and pale ? 



'Mo QUESTIONS FOR CLASS USE, 

126. How is an inflammation caused ? Name its four characteris- 
tics. How may severe bleeding be stopped ? How can you tell 
whether the blood comes from an artery or a vein ? Why should you 
know this ? 

127-8. What is the scrofula? What are "kernels?" How may a 
scrofulous tendency of the system be counteracted ? What kinds of 
food stimulate this disease ? What is the cause of " a cold ? " Why 
loes exposure sometimes cause a cold in the head, sometimes 
on the lungs, and at others brings on a rheumatic attack ? Why 
is a cold dangerous? Ans, It weakens the system and paves the 
way for other diseases. What is the theory of treating a cold ? De- 
scribe the method. What is catarrh ? Cause ? 



DIGESTION AND FOOD. 

133. Why do we need food ? Why will a person starve without 
food? Are the current stories of people who live without food to be 
relied upon ? How much food is needed per day by an adult in 
active exercise?* How much in a year? How does this amount 
vary? 

134. Describe the body as a mould. As an eddy. What does 
food do for us ? What does food contain ? How is this force set 
free? What force is this? How can it be turned into muscular 
motion, mental vigor, etc.? Do we then draw all our power from 
nature ? What becomes of these forces when we are done with 
them? Do we destroy the force we use ? Aits. No matter has been 
destroyed, so far as we know, since the creation and force is equally 
indestructible. 

135. Compare our food to a tense spring. What three kinds of 

* " From experiments performed while living on an exclusive diet of bread, 
ish, meat, and butter, with coflfee and water for drink, we have found that the 
sntire quantity of food require! during twenty-four hours, by a man in full 
health, and taking free exercise L the open air, is as follows : 

Meat. .16 ounces, or i.oo lbs. avoirdupois. 

Bread, 19 " " i-i9 " " 

Butter, or fat, . . , . 3^ " " 0.22 "" '' 

Water, 52 fluid oz. " 3.38 '' '* 

That is to say, rather less than two and a half pounds of solid food, and rather 
over three pints of liquid foodc" — Dalton. 



O IG U STIO N AND FOOD. 22l 

food do we need ? What is nitrogenous food ? Name the common 
forms. What is the characteristic of nitrogenous food ? Why called 
albuminous? What is carbonaceous food ? Its two kinds? 

136. Constituents of sugar? Where are starch and gum ranked? 
Why? Use of carbonaceous food? What becomes of this heat? 
Composition of fat? How does fat compare with sugar in produc- 
ing heat? Name the other uses of the carbonaceous food. Name 
the mineral matters which should be contained in our food. What 
do you say of the abundance and necessity of water ? Ought we 
not to exercise great care in selecting the water we drink?* 

137. Will not the character of our food influence the quantity of 
water? What are the uses of these different minerals? Illustrate 
the importance of salt. Could a person live on one kind of food 
alone? Illustrate. 

138. Describe the effect of living on lean meat« Show the neces- 
sity of a mixed diet. Illustrate. Show the need of digestion. 
Illustrate. What is assimilation? Describe the general plan of 
digestion. What did Berzelius call digestion ? Why ? What amount 
of liquid is daily secreted by the alimentary canal ? 

139. What is the alimentary canal ? How is it lined? How does 
the amaeba digest its fooa? The hydra? Define secretion. De- 
scribe the saliva. How secreted ? 

140. What is the amount? Its organic principle? Its use? 
How soon does it act? How long? What tends to check or in- 
crease the flow of saliva ? 

141. Describe the process of swallowing. The stomach. Its size. 
Its construction. What is the peristaltic movement ? The pylorus ? 
For what does this open ? What is the gastric juice ? 

142. How abundant is it ? To what is its acidity due ? What 
organic principle does it contain? How is its flow influenced? 
What is its use ? Appearance of the food as it passes through the 

* Water, which has passed through lead-pipes, is apt to contain salts of that 
metal, and is therefore open to suspicion. (See Chemistry^ page 160.) Metallic 
lined ice-pitchers, galvanized-iron reservoirs, and many soda-water fountains, art 
liable to the same objection. There are also organic impurities in water equally 
dangerous. (See Chemistry ^X)2igQ 60.) River-water often disseminates the germs 
of typhoid fever and other diseases just as the air scatters the seeds of smallpox 
and scarlet fever (page 93). Thus the great outbreak of cholera in the east of 
London, in 1866, was traced to the contamination of the River Lea, which fur- 
nished the supply of water to that part of the city. The surface water frequently 
flows into a well carrying organic matter to poison its contents. Wells some- 
times receive underground the drainage from grave-yards, manufactories, cess- 
pools, swamps, etc., all of which render the water unfit for use. 



222 QUESTIONS FOR CLASS USE. 

pylorus ? How is pepsin prepared ? Why is not the stomach itself 
digested ? What is the construction of the intestines ? 

143. How are the intestines divided ? What is the duodenum ? 
Why so called ? What juices secreted here ? What is the bile ? 
Describe the liver. What is its weight ? Its construction? Ans, It 
consists of a mass of polyhedral cells only toVo to toVu of an inch 
ia diameter, filling a mesh of capillaries. The capillaries carry the 
blood to and fro, and the cells secrete the bile. What is the cyst ? 
What does the liver secrete from the blood beside the bile ? Is the 
bile necessary to life ? Illustrate. What is its use ? 

144. What is the pancreatic juice ? Its organic principle ? Its 
use ? Appearance of the food when it leaves the duodenum ? De- 
scribe the small intestine. 

145. What is absorption ? In what two ways is the food absorbed ? 
Where does the process commence ? How long does it last ? De- 
scribe the lactealSo Of what general system do they form a part ? 
What do they absorb ? Where do they carry the food ? What do 
the veins absorb ? Where do they carry the food ? How is it modi- 
fied ? 

146. Describe the complexity of the process of digestion. What 
length of time required for digestion in the stomach? May not 
food which require^ little time in the stomach need more in the other 
organs, and vice versa -' Tell the story of Alexis St. Martin. 

147. What time was rsquired to digest an ordinary meal ? Ap- 
ples ? Eggs, raw and coo.*: ed ? Roast beef ? Pork ? Which is the 
king of the meats ? What is 'he nutritive value of mutton ? Lamb ? 
How should it be cooked ? Oc^ectloE to pork ? What is the tri- 
china? Should ham ever be eatec raw? Value of fish? Oysters? 
Milk ? Cheese ? Eggs ? 

148. Bread ? Brown bread ? Are warm biscuit and bread 
healthy? Nutritive value of corn ? The potato? Of ripe fruits? 
Of coffee ? 

149. To what is its stimulating property due ? Its influence on 
the system ? When should it be discarded ? Should children use 
a ay stimulants? Effects of tea? Influence of strong tear* What 
IS the active principle of tea ? Nutritive value of chocolate ? What 
is its active principle ? Story of Linnaeus ? How should tea be 
made ? What is the active principle of tobacco ? 

150. Effects of tobacco? Are these immediate? Effects upon 

* The tannin in tea is shown when a drop falls on a knife-blade. The black 
spot is a tannate of iron— a compound of the acid in the tea and the metalo 



DIGESTION AND FOOD. 223 

youth? Give all the reasons why a young man should not learn to 
use tobacco. What is the active principle of all fermented liquors? 
Does alcohol fortify against the cold ? What is its general influence ? 
What is the effect of cooking food ? W^hat precaution in boiling 
meat ? In roasting ? Object of this high temperature ? 

151. What precaution in making soup? Why is frying an un- 
healthy mode of cooking ? State the five evil results of rapid eating. 
What disease grows out of it ? If one is compelled to eat a meal 
rapidly, as at a railroad station, what should he take? Why? Why 
does a child need more food proportionately than an old person ? 
State the relation of waste to repair in youth, in middle, and in old 
age. What kind and quantity of food does a sedentary occupation 
require ? What caution should students, who have been accustomed 
to manual labor, observe ? 

152. Must a student starve himself? Is there not danger of over- 
eating ? Would not an occasional abstinence from a meal be bene- 
ficial ? Do not most people eat more than is for their good ? 
How should the season regulate our diet?* The climate? Illus- 
trate. What does a natural appetite indicate ? How are we to 
judge between a natural and an artificial longing? What does 
the craving of childhood for sugar indicate ? f What is the effect 
upon the circulation of taking food ? Should we labor or study 
iust before or after a meal ? Why not ? 

153. What time should intervene between our meals ? Is " lunch^ 

* Dr. Hayes, the arctic explorer, says, that the daily ration of the Esquimaux 
is from twelve to fifteen pounds of meat, one-third being fat. On one occasion 
he saw a man eat ten pounds of walrus flesh and blubber at a single meal, (See 
Chemistry, page 228.) The low temperature had a remarkable efi'ect on the 
members of his own party, and some of them were in the habit of drinking the 
contents of the oil-kettle with evident relish. Other travellers narrate the most 
incredible stories of the voracity of the inhabitants of arctic regions. Saritcheff, 
a Russian admiral, tells of a man, who in his presence ate, at a meal, a mess 01 
twenty-eight pounds of boiled rice and butter, although he had already partaken 
of his breakfast. Capt. Cochrane further adds, in narrating this statement, that 
It has himself seen three of the savages consume a reindeer at a sittinj^. 

t It does not follow from this, however, that the firee use of sugar m its sepa- 
rate form is desirable. The ordinary articles of vegetable food contain sugar (or 
starch, which in the body is converted into sugar), in large proportion ; and there 
is good reason to believe that in its naturally-combined form it is both more easily 
digested, and more available for the purposes of nutrition, than when crystallized. 
The ordinary sugar of commerce, moreover, derived from the sugar-cane, is not 
capable of being directly applied to physiological purposes. Cane-sugar is con- 
verted within the body into another kind of sugar, identical with that derived 
from the grape, before it can enter into the circuit of the vital changes. 



22^, QUESTIONS FOR CLASS USE. 

ing" a healthy practice ? Eating just before retiring ? Why should 
care be banished from the table ? Will a regular routine of food be 
beneficial ? 

154. Describe some of the wonders of digestion. What are the 
principal causes of dyspepsia ? How may we avoid that disease ? 

155. What are the mumps ? What care should be taken? 



THE NERVOUS SYSTEM. 

159. What are the organs of the nervous system ? What is the 
general use of this system ? How does it distinguish animals froni 
plants ? What are the vegetative functions ? What is the gray mat- 
ter ? Its use ? The white matter ? Its use ? 

161. Describe the brain. What is its office ? Its size ? Hov7 
does it vary? Illustrate. Name its two divisions. Describe the 
cerebrum. The convolutions. The membranes which bind the 
brain together. What do you say of the quantity of blood which 
goes to the brain ? What does it show ? 

162. What do the convolutions indicate ? What is the use of the 
two halves of the brain ? What theories have been advanced con- 
cerning it ? 

163. What is the effect of removing the cerebrum ? Describe the 
cerebellum. 

164. What is the arbor vitae ? What does this part of the brain 
control ? What is the effect of its being injured ? * Illustrate. De- 
scribe the spinal cord. What is the medulla oblongata ? Describe 
the nerves. 

165. Is each part of the body supplied with its own nerve ? Prove 
It. What are the motory nerves ? The sensory? When will mo- 
tion be lost and feeling remain, and vice versa ? What is meant by 
a transfer of pain ? Illustrate. 

166. Name the three classes of nerves. What are the spinal 
nerves ? Describe the origin of the spinal nerve. What are the 
:ranial nerves ? 

* The tamping-iron, and the skull of the man spoken of on page 163, are pre- 
served in the Warren Anatomical Museum, Boston. It is noticeable that the man 
afterward became changed in disposition, fickle, impatient of restraint, and pro- 
fane, which he was not before. He died epileptic, probably from progressive 
disease of the brain, nearly thirteen years atter the injury.— Parsons. 



THE NEKVOUS SYSTEM, 

167-8. Name the cranial nerves. 

i6g. Describe the sympathetic system. What is its use ? How 
does the brain control all the vital processes ? What is meant by 
the crossing of the cords ? What is the effect ? What exception ir 
the seventh pair of cranial nerves ? What is reflex action ? 

170. Give illustrations. Give instances of the unconscious action 
of the brain.* Can there be feeling or motion in the lower limbs 

* Dr. Carpenter, in the course of a recent lecture at Manchester, England, upot 
the '' Unconscious action of the Brain," gave the following among other illustra- 
tions:—!. We find that when we set ofi in the morning with the intention ot 
going to our place of employment, not only do our legs move without our con- 
sciousness, if we are attending to something entirely different, but we guide our- 
selves in our walk through the streets ; we do not run up against anybody we 
meet ; we do not strike ourselves against the lamp-posts ; and we take the appro- 
priate turns which are habitual to us. It has often happened to myself, and I 
dare say it has happened to everyone of you, that you have intended to go some- 
where else— that when you started you intended instead of going in the direct 
line to which you were daily accustomed, to go a little out of your way to per- 
form some little commission; but you have got into a train of thought and for- 
gotten yourself, and you find that you are half-way along your accustomed track 
before you become aware of it. Now, there, you see, is the same automatic 
action of these sensory ganglia — we see, we hear — for instance, we hear the rum- 
bling of the carriages, and we avoid them without thinking of it— our muscles act 
in respondence to these sights and sounds — and yet all this is done without our 
intentional direction — they do it for us. We arrive at a certain point where we 
are accustomed to stop, and are surprised that we have reached it. You will ask 
me, perhaps, " W^hat is the exciting cause of this succession of actions in walk- 
ing ?" I believe it is the contact of the ground with the foot at each movement. 
We put down the foot, that suggests as it were to the spinal cord the next move- 
ment of the leg in advance, and that foot comes down in its turn ; and so we 
follow with this regular rh^iihmical succession of movements. It is all done: 
through the reflex action of the spinal cord. 

2. The cerebellum has its unconscious action in the processes of respiration, the 
involuntary movements which are made in response to the senses, as in winking, 
starting back at a sound, etc. 

3. The cerebrum acts automatically in cases familiar to all. A large part of our 
mental activity consists of this unconscious work of the brain. There are many 
cases in which the mind has obviously worked more clearly and more successfully 
in this automatic condition, when left entirely to itself, than when we have been 
cudgeling our brains, so to speak, to get the solution. An instance was put on 
record by a gentleman well known in London, the Rev. John De Liefde, a Dutch 
clergyman, who gave it on the authority of a fellow-student who had been at the 
college at which he studied in early life. He had been attending a class in mathe- 
matics, and the professor said to his students one day: '' A question of great 
difficulty has been referred to me by a banker — a very complicated question of 
accounts, which they have not themselves been able to bring to a satisfactory 
issue, and they have asked my assistance. I have been trying, and I cannot re- 
solve it. I have covered whole sheets of paper with calculations, and have not 
been able to make it out Will you try ? " He gave it to them as a sort of prob- 



226 QUESTIONS FOR CLASS USE. 

when the spinal cord is destroyed ? What does the story told byD:t. 
John Hunter show ? Give illustrations of the independent action 
of the spinal cord in animals. 

171. What are the uses of reflex action ? State its value in the 
formation of habits. 

172. How does the brain grow? What laws govern it? What 
must be the effect of constant light-reading ? Of over-study or men. 
tal labor ? State the relation of sleep to repair and waste. How 
many hours does each person need ? What kind of work requires 
most sleep ? 

173. What three stages are there in the effect of alcohol on the 
nervous systems. Describe each. Does alcohol confer any perma- 
nent strength ? 

174. What is the influence of sunlight on the body? Illustraf^- 

175. Name some of the wonders of the brain. 



THE SPECIAL SENSES. 

179. What is a sense ? Name the five senses. To what organ 
do all the senses minister ? If the nerve leading to any organ of 
sense be cut, what would be the effect ? * Sometimes persons lose 
feeling in a limb, but retain motion : why is this ? What is the sense 
of touch sometimes called ? Describe the organ of touch. What 
are the papillae ? Where are they most abundant ?f What are the 

lem, and said he should be extremely obliged to any one who would bring him 
the solution by a certain day. This gentleman tried it over and over again ; he 
covered many slates with figures, but could not succeed in resolving it. He was 
''put on his mettle," and determined to achieve the result. But he went to bed 
on the night before the solution was to be given in, without hav^ing succeededo 
In the morning, when he went to his desk, he found the whole problem worked 
out in his own hand. He was perfectly satisfied that it was his own hand ; and 
this was a very curious part of it — that the result was correctly obtained by a 
process very much shorter than any he had tried. He had covered three or four 
sheets of paper in his attempts, and this was all worked out upon one page, and 
correctly worked, as the result proved. 

* Each organ is adapted to receive a peculiar kind of impression. Hence we 
cannot smell with the eyes nor see with the nose. So that if the nerve communi- 
cating between the brain and any organ be destroyed, that means of knowledge 
is cut off. 

t If we appiv the points of a compass blunted vdth cork to different parts of 



THE SPECIAL SENSES. 227 

uses of this sense ? What special knovvledt^c do we obtain by it ? 
Why do we always desire to handle anything curious ? Can the 
sense of touch always be relied upon? Illustrate. 

i8o. Show how capable this sense is of cultivation. Illustrate. 
What is the tactus eruditus? Illustrate. Tell how one sense can 
Ake the place of another. Give illustrations of the delicacy of 
ouch possessed by the blind. 

i8i. Describe the sense of taste. How can you see the papillae 
yi taste ? 

182. What causes the velvety look of the tongue ? Why do salt 
and bitter flavors induce vomiting ? Why does an acid " pucker " 
the face ? What substances are tasteless ? Illustrate. Has sulphur 
any taste? Chalk ? Sand ? What is the use of this sense ? Does 
it not also add to the pleasures of life ? Why are the acts of eating, 
drinking, etc., thus made sources of happiness ? Describe the or- 
gan of smell. State the intimate relation which exists between the 
senses of smell and taste. Name some common mistakes which 
occur in consequence. 

183. Must the object to be smelled touch the nose ? What is the 
theory of smell ? How do you account for the statement made in 
the note concerning musk and ambergris ? 

184. What are the uses of this sense ? Are agreeable odors 
healthy, and disagreeable ones unhealthy? Describe the organ of 
hearing. 

185. Describe the external ear. What is the tympanum or drum 
of the ear ? Describe the middle ear. Name the bones of the ear. 
Describe their structure. Describe the internal ear. By what other 
name is it known ? What substances float in the liquid which fills 
the labyrinth ? What is their use ? Describe the fibres of Corti. 

186. What do they form ? Use of this microscopic harp? Give 
the theory of sound. Where is the sound, in the external object or 
in the mind? Can there be any sound, then, where there is no 
mind ? What advice is given concerning the care of the ear ? How 
can insects oe removed ? Which sense would you rather lose, hearing 
?r sight ? Does not a blind person always excite more sympathy 
than a deaf one ? How does the sight assist the hearing?* 

the body, we can distinguish the two points at one-twenty-fourth of an inch apart 
on the tongue, one-sixteenth of an inch on the lips, one-twelfth of an inch on the 
tips of the fingers, and one-half inch on the great toe ; while, if they are one inch 
on the cheek, and two inches on the back, they will scarcely produce a separate 
sensation. — Huxley. 
* In hearing^ the attention is more or less characteristic. If we wish to dis 



228 QUE STIO NS FOR CLASS USE. 

187. Describe the eye. Name the three coats of which it is zova^ 
posed? Is it a perfect sphere? Ans, The cornea projects in front, 
and the optic nerve at the back sticks out like a handle, while the 
ball itself has its longest diameter from side to side. How is the 
interior divided ? Object of the crystalline lens ? 

188. How is the crystalline lens kept in place ? Describe the 
liquids which fill the two chambers. What is the pupil ? Describe 
the eyelids. Why is the inner side of the eyelid so sensitive? 
What is the cause of a black eye ? Use of the eyelashes ? Where 
are the oil-glands located ? What is their use ? Describe the 
lachrymal gland. 

190. The lachr}^mal lake. What causes the overflow in old age ? 
Explain the structure of the retina. 

191. Use of the rods and cones. What is the blind spot ? Illus- 
trate. What is the theory of sight ? Illustrate. 

192. State the action of the crystalline lens. Its power of adapt- 
ation. 

193. Cause of near-sightedness ? How remedied ? Cause of 
far-sightedness? How remedied? Do children ever need specta- 
cles? 

194. What is the cataract? How cured ? What care should be 
taken of the eyes ? Should one constantly lean forw^ard over his 
book or work ? What special care should near-sighted children 
take ? By what carelessness may we impair our sight ? Should we 
ever read or write at twilight ? Danger of reading upon the cars ? 
What course should we take when objects get into the eye ? How 
may they be removed ? 

195. Are " eye-stones " useful ? Why we should never use eye- 
washes except upon the advice of a competent physician ? What 
care should be taken with regard to the direction of the light when 
we are at work ? 

tin^ish a distant noise, or perceive a sound, the head inclines and turns in such 
a manner as to present the external ear in the direction of the sound, at the same 
time the eyes are fixed and partially closed. The movement of the lips of his in- 
terlocutor is the usual means by which the deaf man supplies the want of hear- 
ing ; the eyes and the entire head, from its position, having a peculiar and painful 
expression of attention. In looking at the portrait of La Condamine, it was easily 
recognized as that of a deaf person. Even when hearing is perfect, the eyes act 
sometimes as auxiliaries to it. In order to understand an orator perfectly, it 
seems necessary to see him— the gestures and the expression of the face seeming 
to add to the clearness of the words. The lesson of a teacher cannot be well 
understood if any obstacle is interposed between him and the eyes of the listening 
pupil. So that if a pupil's eyes wander, we know that he is not attentive.-' 
Wonders 0/ the Human Body. 



V N C L U S I N, 

197. State some of the benefits of health. Contrast it with sick- 
ness. How were diseases formerly supposed to be caused? What 
remedies were used ? What does modern science teach us to be 
the nature of disease ? 

198. Give some illustrations showing how diseases may be pre- 
vented. Is it probable that the body was intended to give out in any 
one of its organs ? * 

199. What is the first step to be taken in the cure of a disease 't 
What should be the object of medicine ? What is now the chief 
dependence of the best physicians? What do you think concerning 
the common use of patent nostrums? Relate the story told of the 
remedy employed by the African medicine-man. Ought we not to 
use the greatest care in the selection of our physician to secure the 
highest medical skill and cultivation ? 

* '' So long as the phenomena of waste and repair are in harmony — so long, in 
other words, as the builder follows the scavenger — so long man exists in integrity 
and repair— just, indeed, as houses exist. Derange nutrition, and at once degen- 
eration, or rather let us say, alteration begins. Alas ! that we are so ignorant 
that there are many things about our house, which, seeing them weaken, we 
know not how to strengthen. About the brick and the mortar, the frame and the 
rafters, we are not unlearned ; but within are many complexities, many chinks 
and crannies, full in themselves of secondary chinks and crannies, and these so 
small, so deep, so recessed, that it happens every day that the destroyer settles 
himself in some place so obscure, that while he kills, he laughs at defiance. You 
or I meet with an accident in our watch. We consult the watchmaker, and he 
repairs the injury. If we were all that watchmakers, like ourselves, should be, 
a man could be made to keep time until he died from old age or annihilating ac- 
cident. This I firmly and fully believe."— (9^<^ Hours of a Physician, 



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N D E X 



PAGE 

Abdomen 88 

Absorbing power of skin 73 

Absorption of food 123, 145 

Achilles, Tendon of 48 

Adam's apple 83 

Air, Composition of 92 

" Needof 92 

" Action of 92 

Air-cells 87 

Albinos 62 

Albumen 135 

Albuminous bodies 135 

Mcohol 150, 172 

" Effect o^, on nerves 172 

Alimentary canal 139 

Amseba 139 

Anatomy, Definition of 7 

Ankle-joint 35 

Antidotes for poison 209 

Aorta , 114 

Apoplexy 206 

Aqueous humor 1S8 

Arachnoid membrane 161 

Areolar (connective) tissue 66 

Arteries 113 

Arterial blood iii 

Articulation 28 

Asphyxia 98 

Assimilation 138 

Atlas 28 

Auditory nerve 168 

Auricles of the heart 110 



Axis . 



Back-bone 27 

Ball-and-socket joint 31 

Bathing 74 

Beef 147 

Bicuspid teeth 68 

Bicuspid valve 113 

Bile 143 

Black Hole of Calcutta 93 

Bleeding, Checking of 126 

Blood, The 105 

Blood-crystals ..• .. 107 

Blushing 125 

Boils -^9 

Bones, Tie. ... ......... , • • . • 19 

Bow-legs 37 

Brain 161 

" Exercise 172 

Bread 148 

Breast-bone 29 

Breathing 89, 93 

Bronchi 87 

Bronchitis 97 

Bums 204 

Bursa 56 

Canal, Alimentary 139 

" Semi-circular 185 

" Haversian 22 

Canine teeth 68 

Capillaries iib 



INDEX. 



PAGE 

Carbonic acid 92 

*' oxide 94 

Carbonaceous food 135 

Carpus 32 

Cartilage 20 

Casein 135 

Cataract 193 

Catarrh 128 

Cells of blood 105 

** *• brain 159 

" *' lungs 87 

" *' skin 62 

Cement 70 

Cerebellum 163 

Cerebmm 161 

Change of our bodies 121 

Cheese 147 

Chest 29 

Chilblain 78 

C tiocolate 149 

Choking 206 

Choroid 187 

Chyle 144 

Chyme 142 

Ciliary processes 188 

Cilia, The 89 

Circulation 105, 117 

Clavicle 31 

Clothing , 76 

Coagulation 108 

Coccyx 27 

Cochlea 185 

Cofifee 148 

Cold, A 126 

Cold bath 74i 75 

Collar-bone 31 

CoDiplexion, The 63 

Congestion 125 

Connective tissue 66 

Consumption 94, 98 

Cooking of food 150 

Cords, Vocal ... 83 

Cornea 187 

Corn 148 

Corns 78 

Corpuscles 106 

Cortian fibres 185, 190 



Cosmetics 73 

Cotton 76 

Coughing 90 

Cranial nerves 166 

Croup gs 

Crying 91 

Crystalline lens 187 

*' *' Adjustment of 191 

Curvature of the spine 37 

Cuticle^ The 61 

Cutis, The 61 

Dandruff 62 

Decay 7O1 133. '99 

Dentals, The 87 

Dentine 70 

Dermis 61 

Diaphragm 90 

Diastole no 

Diflfusion of gases 94 

Digestion 138 

Digits 31 

Diphtheria 98 

Diseases, etc 36, 54, 77^ 96, 1515, 154 

Disinfectants 204 

Dress 76 

Drinking-water 221 

Dropsy 67, 78 

Drowning 207 

Duct, Thoracic 123 

Duodenum 143 

Dura mater 161 

Dyspepsia , 154 

Ear, The...-. 184 

" -ache 206 

" Things in the 208 

Eating, Regularity in 153 

" Rapid 151 

Eggs 147 

Elbow-joint 32 

Enamel of teeth 70 

Epidermis 61 

Epiglottis 83 

Epilepsy ... ,.-.. 206 

Epithelium ^ 143 

Erysipelas •-.- 77 



SS4 



INDEX. 



PAGE 

Ether 190 

Eustachian tube 185 

Exercise, Muscular 52 

Brain 172 

Expiration 90 

Eye, Tne 187 

''' Adjustment of the ..191-2 

' Muscles of the 47 

'* Things in the 193 

Eyebrows 188 

Eyelids 188 

Eye-stones 194 

Eye-wash 194 

Face, Bones of. . . 25 

Face, Expression of. 172 

Far-sight 191 

Fat-cells 6^ 

Fats, The 136 

Felon 37 

Femur 34 

Fever 207 

Fibrm 108 

Fibula 35 

Fireplace roo 

Fish 147 

Fits 206 

Flannel 76 

Fluids, Digestive 139 

Fontanelles, The 21 

Food, Absorption of 145 

" Cooking of 150 

** Digestion of 138 

" Kinds of 135 

" Need of -. 133 

" Quantity of 151 

Foot, The 35 

Frost-bite 207 

Fruits 148 

Furs 77 

Gall-bladder (cyst) 143 

Ganglion, A .* 56 

" A nerve 159 

Gaping 91 

Gastric-juice 141 

Gelatin 20,67 



PAGE 

Glands, Gastric 144 

'' Lachrymal 188 

" Lymphatic .... 123 

Oil 71 

" Parotid 139 

" Perspiratory.... 72 

*' Salivary 139 

*' Sebaceous 71 

'' Sweat 72 

Glosso-pharyngeal nerve 168 

Glottis 83 

Grinders, The . 68 

Gristle 24 

Gout, The 55 

Habit 171 

Hair, The 63 

Hair-dyes 73 

Hand, The 33 

Haversian canals 23 

Head 25 

Hearing 184 

Heart 109 

Heat, Distribution of 119 

" Regulation of 120 

" Production of 120 

Hiccough 91 

Hinge-joints 33 

Hip, The 34 

" -bones, o 30 

Hot bath 75 

Humerus 31 

Hydra, The 139 

Hygiene, Definition of 9 

Hypoglossal nerve 167 

Ileum 139 

Incisor teeth 68 

Indian com 148 

Inferior vena cava m 

Inflammation 126 

In-growing nails 78 

Innommata 30 

Inspiration ^. . 89 

Internal ear, The 185 

Intestinal glands 144 

Intestines, The , ,,,,..,.. 143 



ZITDEX. 



2S6 



PAGE 

Involuntary muscles 44 

Iris, The i88 

Iron 136, 137 

Ivory 70 

[OINTS. 24, 49 

[ugular vein 119, 123 

Juice, Gastric , 141 

" Intestinal 144 

" Pancreatic 143 

Jumping 52 

Knee-cap, The 35 

'' joint,The 35 

Labials, The 87 

Labyrinth, The 185 

Lachrymal canals 189 

" glands 188 

lake, The i8q 

Lacteals 124, 145 

Lacunae 22, 28 

Lamb 147 

Large intestine 143 

Larynx 83 

Laughing 91 

Laws, Nature's n 

Lens, Crystalline 187 

Levers 46 

Life and death 120 

Ligaments 24 

Light 174 

Linen 76 

Linguals 87 

Liquor, Spirituous 150, 173 

Lime 137 

Liver 143 

Locked-jaw 55 

Lower jaw 25 

Lumbago 56 

Lunching 153 

Lungs, The 88 

*' Constriction of the 96 

Lymph, The 123 

Lymphatic system 123 

March, Story of Dr 180 



PAGB 

Marrow 23 

Mastication 139 

Meat, Cooking of 151 

Medicine 171, 199 

Medulla oblongata 164 

Membrane, Mucous 66 

*' Serous tic 

Metacarpal bones 33 

Milk 147 

Milk-teeth... 68 

Molars 68-9 

Mucous membrane 66 

Mucus 66 

Mumps, The 155 

Muscles of the body 41 

U U U gyg ^^ 

" Contractility of 41 

" Movement of 41 

" Number of 41 

" Tendons of 45 

" Voluntary 44 

Muscular sense 51 

Mutton 147 

Nails, The 65 

*' In-growing 78 

Nasal duct 188 

Nature's laws 11 

N ear-sight 191 

Nerves, The 165 

'* Craaial 166 

" Spinal 166 

*' of motion 165 

" of sensation 165 

" Sympathetic 169 

Nervous system 159 

Nitrogenous food 135 

Nose, The 183 

" Things in the 208 

OcuLi motores. The 166 

Odors 183 

CEsophagus 83 

Oils, The 137 

Old age 151 

Olfactory nerve ; . . . 167 

Optic nerve 187 



INDEX. 



PAGE 

Organs, Definition of 19 

Organs of circulation , 105 

Organs of digestion. . . . „ 138 

*' ** respiration . o 81 

** ** the voice 81 

of liquids 145 

" gases o . . . 145 

Sciition 2r 

Otoliths.... - 185 

Oxygen , 92 

Palate, The 84 

Pancreas 143 

Pancreatic juice , . 143 

Pancreatin 144 

Papillae 64, 65 

Parotid gland. 139 

Patella, The 35 

Pelvis, The 30 

Pepsin 142 

Pericardium 110 

Periosteum 22 

Peristaltic movement 141 

Perspiration, The 72 

Perspiratory glands 72 

Phalanges > 31^ 33 

Pharynx 84 

Phosphorus... 137 

Physiology, Definition of 7 

Pia mater i6i 

Pigment 63 

Plasma 103 

Pleura 89 

Pleurisy 9S 

Pneumogastric nerve 167 

Pneumonia 98 

Poisons 209 

Pork 147 

Potatoes 148 

Processes « . . , 27 

Ptyalin » ,.... 140 

Pulmonary arteries 118 

" veins 119 

Pulse 114 

Pupil.. 188 

Pylorus Z41 



PAGB 

R-Acius .3....... 32 

Rapid eating » 151 

Reaction., 75 

Reflex action. c 169 

R espiration 87, 89 

Retina 187, 1S8 

Rheumatism « 55 

Ribs, The , 28 

Rickets, The 36 

Russian bath, The 75 

Sacrum, The 27, 30 

St. Vitus' s Dance 54 

Saliva, The 139 

Salivary glands 139 

Salt .' 137 

Scapula 31 

Sclerotic coat 187 

Scrofula... 127 

Scurvy 198 

Sea-bathing 76 

Sebaceous glands 71 

Secretion, Definition of 139 

Semi-lunar valves 113 

Sensation 165 

Senses, The loi 

*' of hearing 184 

" " sight 187 

" " smell 183 

" ** taste i8i 

" " touch 179 

Serous membrane no 

Serum 108 

Shoulder-blade 31 

" -joint 31 

Sick, Care of 203 

Sick-room 203 

Sighing 9c 

Sight, Sense of c . 187 

Sinew (tendon) 000. 43 

Skeleton, The ...,, 19 

Skin, Tne 61 

Skull, The o 25 

Sleep . . . = o 172 

^* by medicine 172 

Sleeping-room 93 

Small intestine, The. • c 244 



INDEX. 



237 



PAGE 

Smell, Sense of. 182 

Sneezing 90 

Snoring 90 

Sound, T Iieory of. 186 

Special senses 179 

Speech 85 

Spectacles 192 

Spinal column, The 27 

*'" cord 164 

Spine, The 27 

Spirituous liquors 150, 172 

Spleen 139 

Sprain 38 

Squinting 193 

Stammering ., 99 

Starch 136 

Sternum 29 

Stomach 141 

Stoves 94 

Sugars, The 135 

Sunlight 174 

Sunstroke 207 

Superior vena cava ii3 

Sutures 26 

Swallowing, Act of 140 

Sweat , 72 

" -glands 72 

Swimming 76 

Sympathetic system 169 

Synovial membrane 24 

Synovia 24 

Systole 110 

Tactus eruditus 180 

Tartar 71 

Taste, Sense of 181 

Tea 149 

Tears, The 188 

Teeth, The 68 

" Decay of 70 

" Indestructibility of 70 

** Preservation of 71 

Temperature of the body 120, 219 

Tendons 45 

Theobromine 149 

Thigh 34 

Thoracic duct 123 



FAGK 

Thorax... w^ 

Throat - 8j 

Tibia 35 

Tight-lacing 9(3 

Tissues, Definition of. 24 

Tobacco 149 

Tongue, The 85, 181 

Tooth-ache, The 206 

Touch, Sense of. 179 

Trachea 87 

Transfusion io3 

Tricuspid valve 1x3 

Trifacial nerve 167 

Trypsin... , 144 

Tympanum .... 185 

Ulna, The = 32 

Unconscious action of the brain. . 170, 225 

Valves of the heart m 

»i " »» veins 115 

Vapor bath 75 

Varicose veins 116 

Veins, The 113 

Velocity of the blood 119 

Vena cava 109 

Venous blood m 

" system.... 115 

Ventilation 94 

Ventricles no 

Vertebrae 27 

Vertebral column 27, 28 

Villi of intestines 145 

Vitreous humor 188 

Vocal cords 83 

Vocalization 85 

Voice, The ,.. 84,85 

Voluntary muscles 44 

Walking 50 

Warts 78 

Washing 74 

Water 221 

" in food 136 

Wens 7q 

Windpipe 87 

Wisdom teeth 69 



£38 



INDEX. 



PAGE 

Wonders of the brain 175 

*' ''• digestion i45f i53 

" " ** heart 121 

u tk ti muscles 54 

" " respiration 96 

Wooden 1 76 



Woolen clothing ,,, 77 

Worms 73 

Wounds 125, 205 

Wrist-joint 33 



Yawning . 



Feb-1810Ol 



hghess 




